Multimodal Standardization of Voice Among Four Multicultural Populations

Journal of Voice Vol. 15, No. 2, pp. 194–219 © 2001 The Voice Foundation

Multimodal Standardization of Voice Among Four Multicultural Populations: Fundamental Frequency and Spectral Characteristics *Mary V. Andrianopoulos, †Keith

N. Darrow, and ‡Jie Chen

*Department

of Communication Disorders, University of Massachusetts, Amherst, Massachusetts; and Hearing Science Program, Massachusetts Institute of Technology, Boston, Massachusetts; ‡School of Public Health, Center for Biostatistics, Harvard University, Boston, Massachusetts

†Speech

Summary: A stratified random sample of 20 males and 20 females matched for physiological factors and cultural-linguistic markers were examined to determine differences in fundamental frequency and spectral characteristics during prolongation of three vowels: [a], [i], and [u]. The ethnic-gender breakdown included four sets of five male and five female subjects comprised of Caucasian and AfricanAmerican speakers of standard American English, native Hindi Indian speakers, and native Mandarin Chinese speakers. Acoustic measures were analyzed using the Multidimensional Voice Program (Kay Elemetrics, Lincoln Park, NJ) (Model 4305) from which fundamental frequency and associated acoustic spectra were extracted from a 200-ms sample of each vowel token. Statistically significant group differences for the main effects of culture, race, and gender were found. The acoustic differences found are attributed to biomechanical, physiological, cultural, and linguistic factors. Key Words: Acoustic spectra—Fundamental frequency— Culture—Race—Vowels—Adults—Jitter—Shimmer—Harmonics-to-noise ratio.

INTRODUCTION

sociated with the speaker.1 Typically, a voice is perceived as sounding normal providing that it meets certain expectations associated with a person’s community, society, culture, age, gender, and profession. A voice disorder or voice difference exists when quality, pitch, loudness, and flexibility of a person’s voice differs from the voices of others of similar age, gender, and cultural group.2 The criteria for judging a voice as normal, abnormal, or belonging to a particular cultural group depend on the orientation of the person making the judgment, the manner in which the measurement is obtained, and the normative thresholds or “norms” to which the acquired acoustic data are compared. Empirical research has demonstrated some differences in acquired voice data related to speaking fundamental frequency, spectral measurements, and

The acoustic perceptual qualities of the human voice have been studied for different purposes. From a medical perspective, the human voice is an indicator of the state of health and the severity and/or progression of disease. From an intellectual perspective, the human voice is a means for communicating linguistic information. From a cultural standpoint, the human voice signifies the community and dialect asAccepted for publication August 29, 2000. Address correspondence and reprint requests to Mary Andrianopoulos, Department of Communication Disorders, University of Massachusetts, 6 Arnold House, Amherst, MA 010030410, USA. Portions of this paper were presented at the 28th Voice Foundation Symposium, Philadelphia, PA, June 4, 1999.

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MULTIMODAL STANDARDIZATION OF VOICE AMONG FOUR MULTICULTURAL POPULATIONS aerodynamic characteristics for some cultural groups, however, the data are limited and lack consistency with respect to research methodologies, diagnostic protocols, test standardization, psychometric test properties, and research findings.3-20 Some investigations reported differences in acoustic data among African-American and Caucasian subjects with respect to average fundamental frequency, however, the empirical studies failed to implement control groups based on physiological and linguistic factors such as age, weight, height, language, and dialect of the speaker.3-8,11 Steinsapir et al9 examined racial differences between 41 African-American and 49 Caucasian children between the ages of 3-9 years during steady prolongation of the [a], [i], and [u] vowels. The authors reported no statistically significant differences in average fundamental frequency measurements for these vowels between African-American and Caucasian children. However, Steinsapir et al 9 observed a statistical trend of increased spectral noise whereby African-American subjects demonstrated greater frequency perturbation or jitter for each vowel prolongation compared to Caucasian subjects. Walton and Orlikoff13 examined 50 AfricanAmerican and 50 Caucasian adult males and reported greater frequency perturbation (jitter), significantly greater amplitude perturbation (shimmer), and significantly lower harmonics-to-noise ratios during steady [a], [i], and [u] vowel prolongations evidenced by the African-American males. The authors reported no significant differences in mean fundamental frequency measurements between African-American and Caucasian male subjects for each vowel prolongation.13 Walton and Orlikoff13 subjected the acquired acoustic data to a low-pass filtering process; thus much of the linguistic information was removed from the acoustic signal with respect to formant analyses and other acoustic measurements. Mayo and Manning12 reported no significant differences in race among 20 AfricanAmerican and 20 Caucasian young adult male subjects for mean fundamental frequency during steady [a] vowel prolongation. However, Mayo and Grant14 observed no significant differences between African-American and Caucasian males with respect to spectral noise measurements such as shimmer and signal-to-noise ratio.

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Sapienza18 compared laryngeal aerodynamic and acoustic characteristics of 10 female and 10 male African-American subjects to a control group of 10 female and 10 male Caucasian subjects matched for age, weight, and height. No significant racial differences were reported for mean fundamental frequency of steady [a] vowel prolongation and most aerodynamic measurements (alternating glottal airflow, minimum glottal airflow, and airflow open quotient) with the exception of maximum flow declination rate. African-American male and female subjects demonstrated significantly lower maximum flow declination rates compared to the Caucasian control groups. The author speculated that the higher and lower maximum flow declination rates among Caucasian and African-American subjects, respectively, may be related to formant frequencies and amplitudes in addition to other modest distinctions in the sound spectra responsible for speaker identification.18 Empirical studies on racial differences of acquired acoustic data for other cultures and races are sparse. Perceptual studies involving human listeners have demonstrated that experimental subjects can subjectively perceive gender, race, social dialect, and affect with relatively good reliability providing that the experimental tasks are controlled for number of tokens elicited, duration of voice sample, and nature of the speaking task. Voice differences among cross-cultural speakers were found to increase with an increase in phonetic complexity of the voice signal.21 Moreover, human listeners were found to subjectively perceive racial and phonetic differences during steady vowel prolongations in the absence of linguistic markers with good reliability.9,12,13,22-25 Calibration and standardization of instruments and test protocols to control for contaminating artifacts and reliability of acquired acoustic measurements are recommended.1 If differences do exist between cultures and races with respect to acoustic data, are these differences due to physiological or cultural-racial factors, or a combination of the two? If differences do exist between certain cultures and races, while controlling for physiological factors such as gender, age, height, and weight, are there specific spectral characteristics unique to any one culture, race, or gender? The purpose of this study was to investigate whether differences exist with respect to fundamental frequency, frequency and amJournal of Voice, Vol. 15, No. 2, 2001

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plitude perturbation, noise, tremor-related, and voice irregularity measurements during steady prolongation of the [a], [i], and [u] vowels among male and female subjects belonging to four homogeneous and culturally diverse populations while controlling for reliability of the acoustic measurement. METHODS Subject selection This investigation was conducted on a stratified random sample of 20 males and 20 females matched for the following physiological and cultural-linguistic factors: gender, culture and race, native language and regional dialect, age, weight, height, educational level, proficiency in English, and the number of years subjects resided in the United States and other countries. The majority of the individual subjects were matched within 15% of their age, height, and weight with a counterpart belonging to each of the other three cultures and races. All subjects were required to meet the following criteria: (1) normal articulation, voice, and resonance based on an oral peripheral neuromotor speech examination using the Mayo Clinic procedures;26 (2) normal hearing based on an audiological screening performed in a soundproof booth at 20 dB sound pressure level (SPL) at 0.25, 0.50, 1, 2, 4, 6, and 8 kHz bilaterally; (3) no history of smoking or alcoholism; (4) no history of professional singing or formal voice training; (5) absence of prescription, over the counter, and illicit drug use at the time of testing; (6) no history of neurologic, respiratory, pulmonary, cardiovascular, voice-related, or other medical problems; (7) absence of illness on the day of testing; and (8) Type 1 spectrographic waveforms of the sustained vowel [a] prolongation identified at the time of screening. According to Titze,1 Type 1 signals are nearly periodic waveforms that display no qualitative changes in the analysis segment. Screening and experimental procedures were conducted by the first author of this study, a Caucasian female. Demographic information The culture and race, family and educational background, age (in years), height (in inches), and weight (in pounds) of each subject was determined based on information provided in a written questionnaire Journal of Voice, Vol. 15, No. 2, 2001

completed by each subject prior to the subject selection process. Each subject was asked to list the following: (1) culture and race, (2) place of birth and origin, (3) state and country in which the subject resided for his or her elementary and secondary education, (4) native language and regional dialect spoken in the home and in which the subject was formally educated, (5) number of languages and dialects spoken, (6) number of years the subject resided in other countries and in the United States, (7) culture and race of subject’s parents and grandparents, (8) educational level of subject’s parents and grandparents, and (9) subject’s current educational level. To ensure homogeneity of each group, subjects were selected for inclusion in the study providing that they met the following criteria: (1) the subject was born, raised, and educated for the first 20 years of the his or her life in the same region, state, and country, (2) elementary and secondary education was provided in the subject’s native language and regional dialect, (3) foreign subjects had not resided in the United States or any other countries for more than 3 years since leaving their place of origin, (4) native English speaking subjects of standard American English (SAE) were born and raised in central or western regions of Massachusetts, and (5) foreign subjects spoke English as a second language proficiently. To control for homogeneity within and between groups, subjects were matched and selected for inclusion in the study based on information provided in the completed questionnaire with respect to demographic, physiologic, familial, and specific cultural-linguistic markers. With respect to the place of origin, language and dialect, the four groups selected for study consisted of five male and five female Caucasian and five male and five female African-American subjects born and raised in central or western Massachusetts and native speakers of SAE and a regional dialect consistent with that region, five male and five female subjects born and raised in India and native speakers of the Hindi Indian dialect, and five male and five female subjects born and raised in mainland China and native speakers of the Mandarin Chinese dialect. All subjects were graduate students attending the University of Massachusetts in Amherst.

MULTIMODAL STANDARDIZATION OF VOICE AMONG FOUR MULTICULTURAL POPULATIONS Equipment and experimental environment The experimental procedures, equipment, and tasks were selected based on recommendations outlined by the National Center for Voice and Speech (NCVS) summary statement in an attempt to standardize the research protocol, control for contaminating artifacts, and enhance the reliability of acoustic data collected for study.1 Voice samples were recorded in a soundtreated, double-walled chamber [IAC (Industrial Acoustics Company, Inc., Bronx, NY), Model 1604] with an ambient noise level of 25 dBA. Each subject was seated in a chair and outfitted with a miniature head-mounted professional grade condenser microphone [AKG (Akustiche u. Kino-Geräte Gesellschaft m.b.H., Vienna, Austria) C-410] positioned 45° offaxis mouth-to-microphone distance held constant 1 inch to the right of each subject’s mouth. Voice samples were recorded in analog and digitized onto a Tascam DA-P1 (TEAC Corporation, Nakacho, Japan) digital audiotape (DAT) recorder at a sampling rate of 48 kHz with a PAD of 20 dB. The input level control was adjusted per subject and set in the VU meter in the vicinity of –6 dB during three practice sessions of the vowel [a] prolongation to prevent overloading of the voice recording. The digital peakhold meter was monitored to ensure that the available headroom of the DAT recording did not exceed approximately a –4 dB margin. All recordings were made on high quality SONY (Sony Corporation, Tokyo, Japan) Pro-DAT-Plus (PDP-35C) digital audio tapes per subject. Once the necessary adjustments were made per subject, the settings were held constant and monitored for potential overload to control for consistency of each individual voice recording. Measurements Tasks for fundamental frequency and spectral analyses Test utterances for acoustic voice analysis consisted of three nonspeech tasks classified by the (NCVS) guidelines.1 The three vowels selected for sustained steady vowel prolongation consisted of the [a], [i], and [u] vowels. Each subject was cued to produce sustained and steady prolongations of the [a], [i], and [u] vowels in isolation on a single breath with comfortable and constant pitch and loudness levels. A brief rehearsal was allowed per subject to ensure comprehension of the task and general comfort of the subject prior to the actual recording peri-

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od. For each vowel, three consecutive 600-ms tokens were obtained from which a 200-ms window was extracted from the midpoint of each subject’s three vowel productions for the [a], [i], and [u] vowels to obtain data measurements. For all subjects, an additional three consecutive 600-ms tokens for each of the [a], [i], and [u] vowels were obtained from which a 200-ms window was extracted at the midpoint per vowel for intrameasurer reliability comparisons. In sum, a set of six consecutive tokens per three vowels was obtained on each subject for fundamental frequency and spectral analyses. Extraction of acoustic measurements The Computerized Speech Lab (CSL Model 4300B, 5.X) and the Multidimensional Voice Program (MDVP 4305, 1.34) by Kay Elemetrics were utilized for editing the acoustic signals and extraction of acoustic measurements for each [a], [i], and [u] vowel token, respectively. Each vowel token recording was replayed in analog output of the DAT recorder and routed to the line input of the CSL external module utilizing an RCA output to a BNC (baby N connector) plug connector. For the initial set of analyses, each 600-ms vowel prolongation was captured on the CSL set at sampling rate of 50 kHz. Each vowel token was then edited by setting markers at the juncture at each end of the middle 200-ms section whereby the data outside the marks of each token were trimmed. The edited 200-ms token was then digitized and saved in the host computer’s hard drive for additional analyses. To ensure that each subject exhibited a Type 1 spectrographic waveform,1 the first token of the [a] vowel was examined for voice signal classification using the CSL. Although each subject passed the initial screening procedure, only those subjects identified with a Type 1 spectrogram were included in this investigation. Using the Multidimensional Voice program, each edited and digitized 200-ms token was downloaded and captured on the MDVP at a sampling rate of 50 kHz. Each vowel token was subjected to analyses from which a host of approximately 30 acoustic measurements or parameters were obtained. The MDVP program provides objective or linear measurements of extracted voice data belonging to one of the following eight categories: (1) fundamental frequency information, (2) short-term and long-term frequency perturbation, (3) short-term and long-term amplitude Journal of Voice, Vol. 15, No. 2, 2001

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perturbation, (4) voice break, (5) subharmonic components, (6) voice irregularity, (7) noise related, and (8) tremor related. A detailed description of each parameter, as well as associated abbreviations and the category to which each MDVP parameter belongs, are listed in the Appendix. For practical purposes, the MDVP parameters will be referred to by their abbreviated acronym in the text that follows. Statistical analysis For the [a], [i], and [u] vowels, the individual subject means of values obtained from the three 200-ms tokens for each parameter were used to determine group means, standard deviations, and standard error of measurement calculations. A one-way analysis of variance (ANOVA) and sample t-test statistics were used to determine group mean differences between groups for each dependent variable. Duncan Grouping and Tukey post hoc analyses were performed to identify the group of subjects who contributed to the significant difference between groups per dependent variable for each of the nonspeech tasks. The significance level for ANOVA, sample t-test, Duncan, and Tukey procedures was set at ␣ = 0.05. Normality tests by race and gender per task were applied to all data and were found to be normally distributed at a significance level set at ␣ = 0.05. Reliability Reliability testing was conducted for the three nonspeech vowel tasks for test-retest comparisons to determine intrameasurer reliability. Intrameasurer reliability was conducted on 20% of the subject pool (n = 8) for each of the [a], [i] and [u] isolated vowel prolongations for all the acoustic parameters obtained during the experimental test session. The mean of the three 200-ms tokens for the [a], [i], and [u] vowels were compared to the second set of three tokens per vowel obtained within the experimental session. Pearson r correlations were calculated to establish intrameasurer reliability for the three nonspeech tasks. However, Pearson r correlations were not performed on voice break (DVB, NVB), subharmonic components (DSH, NSH), and voice irregularity (DUV, NUV) measurements given the large numbers of missing data for these parameters. The p values obtained on intrameasurer test-retest procedures are noted in Table 1. Journal of Voice, Vol. 15, No. 2, 2001

RESULTS Personal demographic data: age, height, and weight A statistically significant difference in mean age was found among males. Indian male subjects were noted to be younger in age by approximately 1-2 years compared to Caucasian, African-American, and Chinese male subjects. The mean age of Chinese male subjects was noted to be older by approximately 1-2.5 years compared to the other three male groups (P ≤ 0.05). No significant difference in mean age was noted among Caucasian, African-American, Indian, and Chinese female groups. No significant differences in mean weight and mean height was found for both males and females by race. Demographic data are listed by gender and race in Table 2. Acoustic data and vocal parameters The following statistically significant differences were observed for vocal parameters pertaining to fundamental frequency and spectral measurements extracted from the acoustic signals using the MDVP program during steady prolongation of the three isolated [a], [i], and [u] vowels. Main effect: race Steady vowel [a] prolongation Group mean and standard deviation data related to fundamental frequency and spectral measurements for males and females by culture and race during steady vowel [a] prolongation are listed in Tables 3 and 4. Fundamental frequency information measurements Significant differences in group means were observed among male and female subjects for four (F0, To, Fhi, Flo) of the six extracted vocal parameters related to F0 measurements during steady vowel [a] prolongation. Compared to Caucasian, AfricanAmerican, and Indian male subjects, Chinese males were observed with significantly higher group means for the parameters F0 (F[3, 55] = 3.67, P ≤ 0.02), Fhi (F[3, 55] = 3.34, P ≤ 0.03), Flo (F[3, 55] = 6.99, P ≤ 0.0005), and a significantly lower group mean for the parameter T0 (F[3, 55] = 5.67, P ≤ 0.002). No significant group differences were observed among male subjects for the parameter STD and PFR. Chinese females were observed with sig-

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TABLE 1. Test-Retest Reliability* Vowel [a]

Vowel [i] r

α

Fundamental frequency information measurements F0 0.997 0.000‡ 0.999 0.000‡ T0 0.999 0.000‡ 0.999 0.000‡ Fhi 0.996 0.000‡ 0.999 0.000‡ Flo 0.988 0.000‡ 0.992 0.000‡ STD 0.827 0.010‡ 0.657 0.080† PFR 0.840 0.010‡ 0.572 0.140

0.999 0.999 0.994 0.988 0.930 0.340

0.000‡ 0.000‡ 0.000‡ 0.000‡ 0.001‡ 0.410

Short-term and long-term frequency perturbation Jita 0.839 0.010‡ 0.766 0.030‡ Jitt 0.812 0.010‡ 0.880 0.004‡ RAP 0.802 0.010‡ 0.890 0.003‡ PPQ 0.810 0.002‡ 0.770 0.020‡ sPPQ 0.790 0.020‡ 0.890 0.000‡ vF0 0.870 0.005‡ 0.580 0.140

0.689 0.560 0.570 0.530 0.960 0.810

0.060† 0.150 0.140 0.180 0.000‡ 0.010‡

Short-term and long-term amplitude perturbation ShdB 0.730 0.040‡ 0.890 0.004‡ ‡ Shim 0.730 0.040 0.880 0.004† APQ 0.930 0.001‡ 0.780 0.020† sAPQ 0.820 0.010‡ 0.900 0.003‡ vAm 0.910 0.002‡ 0.780 0.020‡

0.650 0.630 0.710 0.640 0.840

0.080† 0.090† 0.050‡ 0.090† 0.010‡

Noise-related measurements NHR 0.820 0.010‡ VTI 0.200 0.630 SPI 0.890 0.003‡

0.820 0.670 0.970

0.010‡ 0.070 0.000‡

0.640 0.410 0.970

0.090† 0.360 0.000‡

Tremor measurements FTRI 0.710 ATRI 0.990 Fftr 0.550 Fatr 0.900

0.760 0.980 0.740 0.530

0.050‡ 0.003‡ 0.090† 0.360

0.900 0.950 0.700 0.960

0.005‡ 0.050‡ 0.080† 0.040‡

Values

*Intrameasurer †␣

= 0.10.

‡␣

= 0.05.

r

α

Vowel [u]

0.050‡ 0.010‡ 0.200 0.290

r

α

reliability for 20% of the sample (n = 8) using Pearson r.

nificantly higher group means for the parameters F0 (F[3, 56] = 9.12, P ≤ 0.0001), Fhi (F[3, 56] = 4.42, P ≤ 0.007), and Flo (F[3, 56] = 4.19, P ≤ 0.01), compared to Caucasian, African-American, and Indian female subjects. No significant differences in the group means of female subjects were observed for the fundamental frequency–related measurements T0, STD, and PFR.

Short-term and long-term frequency perturbation measurements Significant group differences were observed among male subjects for four (Jita, RAP, PPQ, vF0) of the six extracted parameters related to frequency perturbation measurements during prolongation of the [a] vowel. Caucasian males were observed with significantly higher group means for the parameters Journal of Voice, Vol. 15, No. 2, 2001

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MARY V. ANDRIANOPOULOS ET AL TABLE 2. Male and Female Demographic Data: Mean Age, Height, and Weight Males Caucasian n=5

African-American n=5

Indian n=5

Chinese n=5

Age (years) (SD) Range

25.90 (2.00) 23.40-29.00

24.90 (1.90) 22.20-27.00

24.50 (1.80) 22.10-27.40

26.80 (2.50) 23.10-29.80

Height (in.) (SD) Range

69.40 (1.95) 66.0-71.0

67.80 (1.10) 66.0-69.0

66.00 (5.61) 60.0-71.0

66.60 (4.16) 60.0-71.0

Weight (lb) (SD) Range

173.00 (10.37) 160.00-185.00

163.40 (27.98) 130.00-195.00

153.40 (24.22) 130.00-190.00

144.60 (23.35) 119.00-180.00

Females n=5

n=5

n=5

n=5

Age (years) (SD) Range

24.50 (2.00) 22.40-22.70

25.30 (1.70) 23.50-28.10

23.80 (1.40) 22.00-25.70

24.70 (1.50) 23.10-27.00

Height (in.) (SD) Range

64.80 (2.28) 62.00-67.00

64.60 (3.58) 60.00-68.00

63.60 (2.25) 60.00-66.00

64.40 (1.20) 62.00-65.00

Weight (lb) (SD) Range

153.00 (46.95) 125.00-235.00

151.00 (52.37) 105.00-240.00

137.80 (16.41) 115.00-158.00

122.40 (20.01) 100.00-155.00

Jita (F[3, 55] = 4.60, P ≤ 0.007), and PPQ (F[3, 55] = 3.99, P ≤ 0.01), compared to African-American, Indian, and Chinese male subjects. African-American males were observed with significantly lower group means for the parameters RAP (F[3, 55] = 3.26, P ≤ 0.03), and PPQ (F[3, 55] = 3.99, P ≤ 0.01), compared to the Caucasian, Indian, and Chinese male subjects. Chinese males were observed with a significantly lower group mean for the parameter; vF0 (F[3, 55] = 3.04, P ≤ 0.04), compared to the other three male groups. No significant differences between male groups were noted for the frequency perturbation parameters Jitt and sPPQ. With respect to female subjects, no significant differences were observed between Caucasian, African-American, Indian, and Chinese female groups for all six parameters related to short-term and long-term frequency perturbation measurements (Jita, Jitt, RAP, PPQ, sPPQ, vF0) during prolongation of the [a] vowel.

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Short-term and long-term amplitude perturbation measurements With respect to the five parameters related to amplitude perturbation measurements (ShdB, Shim, APQ, sAPQ, vAM), no significant group differences were observed between Caucasian, African-American, Indian, and Chinese male subjects for all five extracted parameters during vowel [a] prolongation. However, significant differences were observed among the female groups for all four amplitude perturbation measurements for this vowel. The group means of Caucasian and Chinese female groups were significantly higher than that of Indian and African-American female subjects for the parameters ShdB (F[3, 56] = 10.81, P ≤ 0.0001), Shim (F[3, 56] = 10.62, P ≤ 0.0001), APQ (F[3, 56] = 10.10, P ≤ 0.0001), and sAPQ (F[3, 56] = 7.54, P ≤ 0.0003). For the long-term amplitude perturbation parameter vAm, the group mean of Chinese females was sig-

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TABLE 3. Acoustic Measurements and Vocal Parameters of Vowel [a] Prolongation for Males Steady Vowel [$] Prolongation for Male Subjects Caucasian n=5 Symbol

Unit

Mean

SD

African-American n=5 Mean

Indian n=5

Chinese n=5

SD

Mean

SD

Mean

SD

36.67 2.02 39.27 32.64 0.77 1.80

137.60 7.28 143.58 131.43 1.65 2.57

3.95 0.20 7.68 9.61 0.81 1.94

154.21* 6.60* 159.43* 149.86† 1.34 2.27

20.71 0.88 21.37 21.35 0.96 1.39

Short-term and long-term frequency perturbation measurements Jita µs 77.68† 51.97 30.55 12.79 Jitt % 0.98 0.67 2.09 6.58 RAP % 0.58 0.41 0.23* 0.10 PPQ % 0.57† 0.38 0.23† 0.09 sPPQ % 0.81 0.33 0.56 0.12 vF0 % 1.53 0.74 1.07 0.31

45.05 0.62 0.35 0.35 0.76 1.21

26.61 0.36 0.23 0.20 0.36 0.61

37.31 0.57 0.33 0.32 0.57 0.89*

45.41 0.67 0.42 0.35 0.38 0.66

Short-term and long-term amplitude perturbation measurements ShdB dB 0.12 0.12 0.08 0.06 Shim % 1.33 1.31 0.84 0.69 APQ % 1.05 1.01 0.65 0.49 sAPQ % 1.86 1.56 1.24 1.03 vAm % 4.76 3.76 4.85 4.73

0.11 1.27 0.93 1.72 4.33

0.06 0.72 0.43 0.89 2.28

0.15 1.72 1.26 2.32 4.97

0.13 1.47 0.99 1.47 2.32

Voice break–related measurements DVB % 0 NVB — 0

Fundamental frequency information measurements F0 Hz 128.31 26.06 127.56 T0 ms 8.20 1.49 8.37 Fhi Hz 132.92 26.39 133.11 Flo Hz 115.55 19.17 119.97 STD Hz 1.94 1.04 1.42 PFR Semitones 3.40 1.72 2.67

0 0

0 0

0 0

0 0

0 0

0 0

Subharmonic components–related measurements DSH % 0.05 1.18 NSH — 0.07 0.26

0 0

0 0

0 0

0 0

1.69 1

6.11 3.61

Voice irregularity–related measurements DUV % 0.48 1.86 NUV — 0.80 3.10

0.08 0.13

0.30 0.52

1.50 3.14

5.60 11.76

0 0

0 0

0.02 0.01 9.49

0.13 0.03 18.09

0.01 0.01 8.57

0.13 0.03 22.62

0.01 0.01 5.61

0.13 0.03 21.07

0.04 0.01 7.79

0.15 1.23 5.06 1.61

0.33 0.90 2.73 3.99

0.15 0.79 1.03 4.21

0.50 1.71 2.44 2.87

0.23 1.99 2.37 2.26

0.38 2.24 3.79 2.97

0.20 1.10 3.17 1.53

Noise-related measurements NHR % VTI — SPI — Tremor measurements FTRI % ATRI % Fftr Hz Fatr Hz *P

≤ 0.05.

†P

≤ 0.01.

0.12 0.03 18.28 0.44 1.67 6.10* 3.03

0 0

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MARY V. ANDRIANOPOULOS ET AL TABLE 4. Acoustic Measurements and Vocal Parameters of Vowel [a] Prolongation for Females Steady Vowel [$] Prolongation for Female Subjects Caucasian n=5

African-American n=5

Indian n=5

Chinese n=5

Symbol

Unit

Mean

SD

Mean

SD

Mean

SD

Mean

SD

F0 T0 Fhi Flo STD PFR

Hz ms Hz Hz Hz Semitones

233.46 4.34 241.64 225.94 2.14 2.07

27.61 0.48 25.87 27.52 1.08 0.80

227.99 4.39 235.08 216.30 2.34 2.47

9.13 0.17 7.76 13.73 0.85 0.92

251.64 4.04 265.25 336.69 3.06 2.80

34.23 0.50 48.94 26.46 2.13 1.42

266.73† 3.92 280.94† 253.01† 3.06 2.53

48.32 1.10 54.71 43.58 1.44 1.12

Short-term and long-term frequency perturbation measurements Jita µs 33.65 20.04 21.35 7.42 Jitt % 0.76 0.40 1.09 2.38 RAP % 0.46 0.25 0.29 0.11 PPQ % 0.44 0.23 0.27 0.08 sPPQ % 0.58 0.34 0.46 0.12 vF0 % 0.96 0.49 1.04 0.39

33.37 0.88 0.53 0.52 0.62 1.19

20.76 0.64 0.39 0.38 0.33 0.75

32.03 0.84 0.52 0.47 0.58 1.13

17.35 0.53 0.33 0.29 0.28 0.43

Short-term and long-term amplitude perturbation measurements ShdB dB 0.17† 0.04 0.09 0.03 Shim % 1.97† 0.51 0.99 0.40 APQ % 1.35† 0.39 0.66 0.28 sAPQ % 1.98† 0.77 1.11 0.43 vAm % 5.92 2.81 4.10* 1.50

0.11 1.26 0.87 1.41 5.68

0.07 0.83 0.58 0.99 4.88

0.19† 2.19† 1.46† 2.35† 9.08†

0.08 0.85 0.55 0.84 4.22

Voice break–related measurements DVB % 0 NVB — 0

0 0

0 0

0 0

0 0

0 0

0 0

Subharmonic components–related measurements DSH % 0.10 0.40 NSH — 0.07 0.26

0 0

0 0

0 0

0 0

0.42 0.53

1.28 1.60

Voice irregularity–related measurements DUV % 0 0 NUV — 0 0

0 0

0 0

2.60 3.93

7.98 15.23

0 0

0 0

Noise-related measurements NHR — VTI — SPI — Tremor measurements FTRI % ATRI % Fftr Hz Fatr Hz *P

≤ 0.05.

†P

≤ 0.01.

Journal of Voice, Vol. 15, No. 2, 2001

0 0

0.11 0.03 19.01

0.03 0.01 7.47

0.10 0.02* 12.50

0.02 0.01 6.25

0.12 0.03 17.40

0.01 0.01 7.39

0.11 0.03 17.30

0.02 0.01 6.42

0.27 1.84 2.96 2.98

0.27 1.62 1.67 1.65

0.33 1.17 2.18 2.95

0.14 0.52 1.17 1.59

0.26 2.11 2.08 0.59

0.12 1.56 0.97 0.97

0.27 1.94 2.08 0.13

0.10 1.06 1.20 1.13

MULTIMODAL STANDARDIZATION OF VOICE AMONG FOUR MULTICULTURAL POPULATIONS nificantly higher, whereas the group mean of African-American females was significantly lower (F[3, 56] = 5.05, P ≤ 0.004). Measurements related to voice breaks, subharmonic components, voice irregularity, noise, and tremor One-way ANOVA statistics were not applied to acoustic measurements related to voice breaks (DVB, NVB), subharmonic components (DSH, NSH), and voice irregularity (DUV, NUV) parameters due to the large number of missing data for both male and female groups regardless of culture and race during steady vowel [a] prolongation. These vocal parameters were frequently observed to be either not calculated or reported by the MDVP program, presumably since acquired acoustic data were obtained on subjects with normal voices. For the noiserelated measurements (NHR, VTI, SPI), no significant differences in group means were observed between Caucasian, African-American, Indian, and Chinese male subjects. With respect to females, the group mean of African-American females was significantly lower than that of Caucasian, Indian, and Chinese female groups only for the noise-related parameter VTI (F[3, 56] = 3.90, P ≤ 0.01). No significant differences among female groups regardless of culture and race were observed for the noise-related parameters NHR and SPI. With respect to tremor-related measurements (FTRI, ATRI, Fftr, Fatr), no significant differences in group means were observed among both male and female groups with the exception of males for the parameter Fftr. The group mean of Caucasian males was significantly higher than that of African-American, Indian, and Chinese male subjects for the Fftr parameter during vowel [a] prolongation (F[3, 54] = 3.74, P ≤ 0.02). Steady vowel [i] prolongation Group mean and standard deviation data related to fundamental frequency and spectral measurements for males and females by culture and race for the [i] vowel are listed in Tables 5 and 6. Fundamental frequency information measurements For male and female groups, significant differences were noted for four (F0, T0, Fhi, Flo) of the six parameters related to fundamental frequency measurements during steady vowel [i] prolongation. No sig-

203

nificant differences were observed for two (STD, PFR) of the six fundamental frequency parameters among both male and female groups regardless of culture and race for this vowel. Compared to Caucasian, African-American, and Indian male subjects, Chinese males were observed to have significantly higher group means for the parameters F0 (F[3, 56] = 5.96, P ≤ 0.001), Fhi (F[3, 56] = 5.80, P ≤ 0.002), Flo (F[3, 56] = 10.41, P ≤ 0.0001), and a significantly lower group mean for the parameter T0 (F[3, 56] = 6.38, P ≤ 0.001). With respect to female subjects, Chinese females were observed with significantly higher group means for the parameters F0 (F[3, 56] = 5.43, P ≤ 0.002), Fhi (F[3, 56] = 4.67, P≤ 0.006), Flo (F[3, 56] = 6.61, P ≤ 0.001), and a significantly lower group mean for the parameter T0(F[3, 56] = 5.37, P ≤ 0.003), compared to subjects belonging to the other three cultural and racial groups during vowel [i] prolongation. Short-term and long-term frequency perturbation measurements Only one long-term parameter (sPPQ) among male groups and two short-term parameters (Jitt and PPQ) among female groups of the total six frequency perturbation measurements were significant during steady vowel [i] prolongation. The group mean of Indian males was significantly higher, whereas the group mean of African-American males was significantly lower among male subjects for the sPPQ parameter (F[3, 56] = 2.99, P ≤ 0.04). No significant differences were observed between Caucasian, African-American, Indian, and Chinese male groups for the short-term and long-term perturbation measurements Jita, Jitt, RAP, PPQ, and vF0. The group mean of Caucasian females was significantly higher, whereas the group mean of African-American females was significantly lower than that of Indian and Chinese female groups for the parameters Jita (F[3, 56] = 3.62, P ≤ 0.02) and PPQ (F[3, 56] = 3.03, P ≤ 0.04). No significant differences were observed among the female groups regardless of culture and race for the parameters Jitt, RAP, sPPQ, and vF0. Short-term and long-term amplitude perturbation measurements Significant group differences were observed between Caucasian, African-American, Indian, and Journal of Voice, Vol. 15, No. 2, 2001

204

MARY V. ANDRIANOPOULOS ET AL TABLE 5. Acoustic Measurements and Vocal Parameters of Vowel [i] Prolongation for Males Steady Vowel [i] Prolongation for Male Subjects Caucasian n=5

African-American n=5

Indian n=5

Chinese n=5

Symbol

Unit

Mean

SD

Mean

SD

Mean

SD

Mean

SD

F0 T0 Fhi Flo STD PFR

Hz ms Hz Hz Hz Semitones

125.90 8.09 130.35 119.88 1.43 2.53

17.25 1.18 16.88 18.30 0.64 1.06

140.86 7.55 147.01 128.31 2.18 3.00

38.35 1.80 41.85 24.10 1.82 2.04

139.60 7.17 146.27 132.96 2.20 2.60

4.91 0.25 4.85 5.89 0.78 0.83

162.36† 6.27† 168.53† 156.77† 1.75 2.27

22.15 0.91 21.93 22.16 0.81 0.70

57.32 0.86 0.51 0.50 0.70 1.11

58.02 0.79 0.47 0.44 0.40 0.60

Short-term and long-term frequency perturbation measurements Jita us 59.05 48.77 60.53 28.08 Jitt % 0.72 0.59 0.78 0.27 RAP % 0.42 0.36 0.47 0.17 PPQ % 0.41 0.33 0.45 0.16 sPPQ % 0.66 0.36 0.62* 0.14 vF0 % 1.18 0.61 1.39 0.71

72.11 1.02 0.59 0.58 0.94* 1.58

36.84 0.54 0.33 0.33 0.35 0.58

Short-term and long-term amplitude perturbation measurements 0.02 0.07 0.04 ShdB dB 0.05† Shim % 0.57† 0.23 0.82 0.49 APQ % 0.47† 0.21 0.66 0.32 sAPQ % 1.13† 0.63 1.20 0.32 vAm % 3.44 3.37 4.91 2.24

0.08 0.89 0.69 1.46 3.61

0.05 0.54 0.39 0.67 2.19

0.10† 1.15† 0.89† 1.74† 4.21

0.03 0.39 0.28 0.62 2.08

Voice break–related measurements DVB % 0 NVB

0 0

0 0

0 0

0 0

0 0

0 0

Subharmonic components–related measurements DSH % 0 0 NSH 0 0

0 0

0 0

0 0

0 0

0 0

0 0

Voice irregularity–related measurements DUV % 0 0 NUV 0 0

0 0

0 0

0 0

0 0

0 0

0 0

Noise-related measurements NHR 0.12 VTI SPI 9.38

0.03 0.03 1.38

0.13 0.01 13.10

0.02 0.03 4.30

0.13 0.01 21.10†

0.10 0.01 15.05

0.03 0.03 7.84

0.01

Tremor measurements FTRI % ATRI % Fftr Hz Fatr Hz

0.34 0.57 2.59 2.24

0.15 0.40 1.38 1.33

0.36 0.84 2.97 2.69

0.07 0.56 2.84 1.14

0.40 0.35 4.49 0.35

0.39 1.76† 5.04 2.43

0.09 1.12 6.97 1.59

*

P ≤ 0.05.

†

P ≤ 0.0.1

0 0

Chinese subjects for both males and females for four (ShdB, Shim, APQ, sAPQ) of the five amplitude

Journal of Voice, Vol. 15, No. 2, 2001

0.02 0.03 13.09 0.59† 0.80 4.82 1.74

perturbation measurements for the vowel [i] prolongation. No significant difference between the group

MULTIMODAL STANDARDIZATION OF VOICE AMONG FOUR MULTICULTURAL POPULATIONS

205

TABLE 6. Acoustic Measurements and Vocal Parameters of Vowel [i] Prolongation for Females Steady Vowel [i] Prolongation for Female Subjects Caucasian n=5 Symbol

Unit

SD

Mean

SD

Fundamental frequency information measurements F0 Hz 242.35 25.01 245.67 T0 ms 4.17 0.40 4.08 Fhi Hz 255.00 24.65 257.10 Flo Hz 232.12 24.92 233.49 STD Hz 2.71 1.37 2.29 PFR Semitones 2.67 1.11 2.80

9.87 0.17 12.57 10.22 0.66 0.68

262.17 3.88 280.13 248.28 2.95 2.87

37.23 0.48 45.56 30.50 2.42 1.25

280.92† 3.62† 293.63† 269.27† 2.69 2.53

36.78 0.49 40.38 32.44 1.18 0.99

Short-term and long-term frequency perturbation Jita ␮s 48.38 32.28 Jitt % 1.14 0.70 RAP % 0.69 0.42 PPQ % 0.66 0.40 sPPQ % 0.72 0.43 vF0 % 1.14 0.63

18.94* 0.47 0.29 0.26* 0.42 0.93

15.19 0.39 0.24 0.22 0.16 0.28

30.61 0.90 0.55 0.51 0.62 1.05

31.00 1.08 0.67 0.59 0.57 0.68

23.68 0.65 0.40 0.34 0.44 0.96

23.00 0.59 0.39 0.26 0.31 0.40

Short-term and long-term amplitude perturbation ShdB dB 0.11 0.02 Shim % 1.21 0.27 APQ % 0.84 0.22 sAPQ % 1.26 0.40 vAm % 5.01 2.26

0.10 1.16 0.78 1.12 5.39

0.03 0.31 0.17 0.32 3.80

0.14 1.59† 1.06 1.49 6.04

0.08 0.97 0.60 0.72 4.38

0.17† 1.98† 1.34† 1.90† 6.89

0.07 0.76 0.49 0.65 4.10

Voice break–related measurements DVB % 0 NVB 0

0 0

0 0

0 0

0 0

0 0

0 0

Subharmonic components–related measurements DSH % 0 0 NSH 0 0

0.56 0.80

2.15 3.10

1.88 2.60

3.33 4.61

0.21 0.13

0.81 0.52

Voice irregularity–related measurements DUV % 0 0 NUV 0 0

0 0

0 0

1.82 2.93

7.06 11.36

0.10 0.07

0.40 0.26

Noise-related measurements NHR VTI SPI

≤ 0.05.

†P

≤ 0.01.

0 0

Mean

Chinese n=5

Mean

*P

SD

Indian n=5

SD

Tremor measurements FTRI % ATRI % Fftr Hz Fatr Hz

Mean

African-American n=5

0.09 0.03 23.38†

0.03 0.01 13.13

0.09 0.03 9.92

0.02 0.01 10.79

0.09 0.04 10.60

0.03 0.01 5.44

0.09 0.04 16.19

0.03 0.02 10.38

0.33 1.41 2.79 2.61

0.20 1.12 2.94 1.44

0.27 1.16 3.28 2.28

0.13 1.05 1.75 0.92

0.26 0.86 2.70 3.33

0.15 0.30 1.20 2.51

0.23 1.90 2.58 2.05

0.08 1.64 1.47 1.17

Journal of Voice, Vol. 15, No. 2, 2001

206

MARY V. ANDRIANOPOULOS ET AL

means of both male and female subjects regardless of culture and race was observed for the vAm parameter during vowel [i] prolongation. The group mean of Chinese males was significantly higher, whereas the group mean of Caucasian males was significantly lower than that of African-American and Indian male groups for the parameters ShdB (F[3, 56] = 4.45, P ≤ 0.01), Shim (F[3, 56] = 4.69, P ≤ 0.005), APQ (F[3, 56] = 4.77, P ≤ 0.005), and sAPQ (F[3, 56] = 3.51, P ≤ 0.02). With respect to females, the group mean of Chinese females was significantly higher than that of Caucasian, AfricanAmerican, and Indian females for the parameters ShdB (F[3, 56] = 5.05, P ≤ 0.004), APQ (F[3, 56] = 5.69, P ≤ 0.002), and sAPQ (F[3, 56] = 5.72, P ≤ 0.002). For the Shim parameter, the group means of both Chinese and Indian female subjects were significantly higher than that of Caucasian and AfricanAmerican females (F[3, 56] = 5.13, P ≤ 0.003). Measurements related to voice breaks, subharmonic components, voice irregularity, noise, and tremor As reported for the acoustic data obtained during steady vowel [a] prolongation, ANOVA statistics were also not applied to acoustic data pertaining to the [i] vowel for acoustic measurements related to voice breaks (DVB, NVB), subharmonic components (DSH, NSH), and voice irregularity (DUV, NUV) for reasons previously stated. For noise-related measurements (NHR, VTI, SPI), no significant differences in group means were observed between male subjects regardless of culture and race for NHR and VTI parameters with the exception of the SPI parameter. The group mean of Indian males was significantly higher than that of Caucasian, African-American, and Chinese male subjects for the SPI parameter (F[3, 56] = 5.68, P ≤ 0.002). For tremor-related measurements (FTRI, ATRI, Fftr, Fatr), the group mean of Indian males was significantly higher than that of Caucasian, African-American, and Chinese males for the FTRI parameter (F[3, 52] = 4.16, P ≤ 0.01). The group mean of Chinese males was significantly higher for the ATRI parameter compared to the other three male groups (F[3, 40] = 6.51, P ≤ 0.001). No significant differences in group means were observed for two (Fftr and Fatr) of the four tremor-related measurements for male groups regardless of culture

Journal of Voice, Vol. 15, No. 2, 2001

and race. With respect to females, no significant differences in group means were observed between female groups regardless of culture and race for noise-related parameters NHR and VTI. However, the group mean of Caucasian females was significantly higher than that of African-American, Indian, and Chinese female groups for the noiserelated parameter SPI, (F[3, 56] = 5.48, P ≤ 0.002). No significant differences in group means among female subjects regardless of culture and race were observed for all four tremor-related parameters (FTRI, ATRI, Fftr, fatr). Steady vowel [u] prolongation Group mean and standard deviation data related to fundamental frequency and spectral measurements for males and females by culture and race for the [u] vowel are listed in Tables 7 and 8. Fundamental frequency information measurements Statistically significant differences between the group means of both male and female subjects by culture and race were observed for four (F0, T0, Fhi, Flo) of the six fundamental frequency measurements during steady vowel [u] prolongation. No significant differences were observed among male and female subjects by culture and race for two fundamental frequency parameters (STD and PFR) for this vowel. The group means of Chinese males were significantly higher for the parameters F0 (F[3, 56] = 4.05, P ≤ 0.01), Fhi (F[3, 56] = 4.05, P ≤ 0.01) and Flo (F[3, 56] = 5.37, P ≤ 0.003), compared to Caucasian, AfricanAmerican, and Indian male subjects. The group means of Caucasian males were significantly lower than that of African-American, Indian, and Chinese males for the parameter Flo (F[3, 56] = 5.37, P ≤ 0.003). For the parameter To the group mean of Chinese males was significantly lower, whereas the group mean of Caucasian males was significantly higher compared to African-American and Indian males (F[3, 56] = 4.33, P ≤ 0.003). With respect to female subjects, Chinese females were observed to have significantly higher group means for the parameters F0 (F[3, 56] = 7.31, P ≤ 0.0003), Fhi (F[3, 56] = 7.20, P ≤ 0.0004), Flo (F[3, 56] = 6.42, P ≤ 0.001), and a significantly lower group mean for the parameter To (F[3, 56] = 6.86, P ≤ 0.0005) compared to female

MULTIMODAL STANDARDIZATION OF VOICE AMONG FOUR MULTICULTURAL POPULATIONS

207

TABLE 7. Acoustic Measurements and Vocal Parameters of Vowel [u] Prolongation for Males Steady Vowel [u] Prolongation for Male Subjects Caucasian n=5 Symbol

Unit

Mean

SD

African-American n=5 Mean

Fundamental frequency information measurements F0 Hz 129.92 14.06 146.01 T0 ms 7.79† 0.86 7.36 Fhi Hz 134.92 14.19 152.20 Flo Hz 123.36† 14.42 136.80 STD Hz 1.33 0.42 1.90

Indian n=5

Chinese n=5

SD

Mean

SD

Mean

SD

42.49 1.92 42.54 36.63 1.58

143.09 7.00 149.31 137.82 1.71

6.58 0.31 8.45 7.14 0.88

162.25† 6.30† 167.31† 157.58† 1.40

23.78 0.98 22.98 24.89 0.43

Short-term and long-term frequency perturbation measurements Jita ␮s 38.69 18.96 53.44 47.63 Jitt % 0.49* 0.21 0.69 0.57 RAP % 0.29 0.13 0.41 0.35 PPQ % 0.29* 0.13 0.40 0.33 sPPQ % 0.50 0.15 0.61 0.25 vF0 % 1.04 0.38 1.25 0.67

72.92* 1.05* 0.64* 0.60* 0.81† 1.19

52.14 0.76 0.47 0.43 0.43 0.61

33.81* 0.52 0.31 0.31 0.48 0.88

33.84 0.45 0.28 0.26 0.19 0.31

Short-term and long-term amplitude perturbation measurements ShdB dB 0.06 0.03 0.08 0.03 Shim % 0.65 0.39 0.85 0.33 APQ % 0.56 0.39 0.71 0.35 sAPQ % 1.23 0.91 1.42 0.81 vAm % 4.16 3.30 5.05 3.55

0.12† 1.40† 0.98† 1.73 4.13

0.07 0.81 0.50 0.45 1.62

0.06 0.69 0.54 1.09 2.82

0.02 0.25 0.22 0.57 1.70

Voice break–related measurements DVB % 0 NVB 0

0 0

0 0

0 0

0 0

0 0

0 0

Subharmonic components–related measurements DSH % 0 0 NSH 0 0

0 0

0 0

0 0

0 0

0 0

0 0

Voice irregularity–related measurements DUV % 0.04 0.16 NUV 0.07 0.26

0 0

0 0

0 0

0 0

0 0

0 0

Noise-related measurements NHR VTI SPI Tremor measurements FTRI % ATRI % Fftr Hz Fatr Hz *P

≤ 0.05.

†P

≤ 0.01.

0 0

0.12 0.02 58.31

0.04 0.01 19.35

0.12 0.02 60.32

0.02 0.01 26.79

0.14 0.03 79.98

0.01 0.01 41.03

0.11 0.02 75.27

0.03 0.01 36.48

0.29 0.94 2.99 2.12

0.09 0.88 1.59 1.31

0.33 1.55 3.28 3.70

0.11 1.92 5.32 2.64

0.37 2.20 4.05 3.66

0.26 1.40 4.18 2.16

0.34 1.72 3.91 4.00

0.18 1.79 2.97 3.97

Journal of Voice, Vol. 15, No. 2, 2001

208

MARY V. ANDRIANOPOULOS ET AL TABLE 8. Acoustic Measurements and Vocal Parameters of Vowel [u] Prolongation for Females Steady Vowel [u] Prolongation for Female Subjects Caucasian n=5 Symbol

Unit

Mean

SD

African-American n=5 Mean

Indian n=5

Chinese n=5

SD

Mean

SD

Mean

SD

23.17 0.35 23.39 22.62 0.68 0.52

263.78 3.85 275.31 253.58 2.73 2.60

34.85 0.44 37.42 33.28 0.85 0.83

295.03† 3.46† 307.68† 280.80† 3.10 2.53

40.20 0.52 43.43 35.15 1.44 1.06

Short-term and long-term frequency perturbation measurements Jita ␮s 34.56 14.33 28.53 15.26 Jitt % 0.82 0.31 0.72 0.35 RAP % 0.50 0.19 0.44 0.22 PPQ % 0.48 0.18 0.41 0.20 sPPQ % 0.52 0.15 0.53 0.19 vF0 % 0.91 0.21 1.14 0.31

29.33 0.78 0.48 0.45 0.61 1.03

6.69 0.25 0.15 0.15 0.23 0.29

27.23 0.80 0.48 0.46 0.53 1.03

15.76 0.51 0.31 0.29 0.25 0.38

Fundamental frequency information measurements F0 Hz 242.06 26.92 256.82 T0 ms 4.18 0.43 3.93 Fhi Hz 251.35 29.26 267.26 Flo Hz 234.74 26.40 246.87 STD Hz 2.18 0.51 2.89 PFR Semitones 2.20 0.86 2.47

Short-term and long-term amplitude perturbation measurements ShdB dB 0.07 0.02 0.06† 0.01 Shim % 0.84 0.21 0.65 0.16 APQ % 0.59 0.16 0.44 0.10 sAPQ % 1.13 0.49 1.01 0.66 vAm % 4.99 3.38 5.64 4.06

0.10 1.19† 0.91† 1.26 4.79

0.04 0.49 0.55 0.59 2.72

0.10 1.11 0.77 1.25 6.01

0.03 0.40 0.28 0.46 3.32

Voice break–related measurements DVB % 0 NVB 0

0 0

0 0

0 0

0 0

0 0

0 0

Subharmonic components–related measurements DSH % 0 0 NSH 0 0

0 0

0 0

0 0

0 0

0 0

0 0

Voice irregularity–related measurements DUV % 0 0 NUV 0 0

0 0

0 0

0 0

0 0

0 0

0 0

Noise-related measurements NHR VTI SPI Tremor measurements FTRI % ATRI % Fftr Hz Fatr Hz *P

≤ 0.05.

†P

≤ 0.01.

Journal of Voice, Vol. 15, No. 2, 2001

0 0

0.11 0.03 73.10

0.03 0.01 18.17

0.10 0.02 64.76

0.02 0.01 37.63

0.11 0.02 71.67

0.01 0.01 26.23

0.10 0.02 72.20

0.02 0.01 32.98

0.23 1.27 2.61 2.74

0.10 1.05 2.06 1.48

0.24 1.45 3.49 2.33

0.14 1.15 1.48 1.43

0.42 0.98 2.33 2.47

0.38 0.81 1.20 1.67

0.30 1.54 2.71 2.30

0.14 1.65 1.09 1.36

MULTIMODAL STANDARDIZATION OF VOICE AMONG FOUR MULTICULTURAL POPULATIONS subjects belonging to the other two cultural and racial groups during steady vowel [u] prolongation. Short-term and long-term frequency perturbation measurements Significant group differences were observed between Caucasian, African-American, Indian, and Chinese male subjects for five (Jita, Jitt, RAP, PPQ, sPPQ) of the six perturbation measurements for the [u] vowel. No significant difference among the group means for male subjects regardless of culture and race was observed for the parameter vF0, during prolongation of the [u] vowel. The group mean of Indian males was significantly higher, whereas the group mean of Chinese males was significantly lower for the parameter Jita (F[3, 56] = 2.85, P ≤ 0.05). For the parameters Jitt and PPQ, the group means of Indian males were significantly higher, whereas the group means of Caucasian males were significantly lower (F[3, 56] = 3.46, P ≤ 0.02 and F[3, 56] = 3.26, P ≤ 0.03, respectively). Moreover, the group means of Indian males were significantly higher than that of Caucasian, African-American, and Chinese male subjects for the parameters RAP (F[3, 56] = 3.45, P ≤ 0.02) and sPPQ (F[3, 56] = 4.52, P ≤ 0.01). With respect to female subjects, no significant differences were observed between the females groups regardless of culture and race for all six short-term and long-term frequency perturbation measurements (Jita, Jitt, RAP, PPQ, sPPQ, vF0) for steady vowel [u] prolongation. Short-term and long-term amplitude perturbation measurements Significant group differences were observed between cultural and racial groups among male and female subjects for three (ShdB, Shim, APQ) of five amplitude perturbation measurements. No significant differences between the group means for male and female subjects regardless of race were observed for two amplitude perturbation parameters (sAPQ and vAm). The group means of Indian males were significantly higher than that of Caucasian, AfricanAmerican and Chinese male subjects for the parameters ShdB (F[3, 56] = 6.80, P ≤ 0.001), Shim (F[3, 56] = 7.33, P ≤ 0.0003), and APQ (F[3, 56] = 4.35, P ≤ 0.01). With respect to the females subjects, the group mean of African-American females was significantly lower for the parameter ShdB (F[3, 56] =

209

7.21, P ≤ 0.0004), whereas the group mean of Indian females was significantly higher for the parameters Shim (F[3, 56] = 7.80, P ≤ 0.0002) and APQ (F[3, 56] = 6.12, P ≤ 0.001) than that of Caucasian and Chinese female groups. Measurements related to voice breaks, subharmonic components, voice irregularity, noise, and tremor As reported above with regard to the [a] and [i] vowel prolongations, ANOVA statistics were also not applied for the [u] vowel data for similar reasons with respect to acoustic measurements related to voice breaks (DVB, NVB), subharmonic components (DSH, NSH) and voice irregularity (DUV, NUV). With respect to noise-related (NHR, VTI, SPI) and tremor-related (FTRI, ATRI, Fftr, Fatr) measurements, no significant group differences were observed for males and females regardless of culture and race for steady vowel [u] prolongation. Main effect: gender Significant differences for the main effect gender by culture and race for the three vowel tasks are illustrated in Table 9. Steady vowel [a] prolongation Fundamental frequency information measurements. The following statistically significant differences for the main effect gender were observed between the group means of males and females among Caucasian, African-American, Indian, and Chinese cultures and races for the six parameters related to fundamental frequency measurements during steady vowel [a] prolongation. For Caucasian subjects, the group means of males were significantly lower than that of females for the parameters F0 (F[1, 28] = 115.03, P ≤ 0.0001), Fhi (F[1, 28] = 129.87, P ≤ 0.0001), and Flo (F[1, 28] = 162.50, P ≤ 0.0001). The group means of Caucasian males were significantly higher than that of Caucasian females for the parameters T0 (F[1, 28] = 91.05, P ≤ 0.0001) and PFR (F[1, 28] = 7.39, P ≤ 0.01). No significant difference between Caucasian males and females was observed for the parameter STD. For African-American subjects, the group means of males were significantly lower than that of females for the parameters F0 (F[1, 28] = 105.92, P ≤ 0.0001), Fhi (F[1, 28] = Journal of Voice, Vol. 15, No. 2, 2001

210

MARY V. ANDRIANOPOULOS ET AL TABLE 9. Test of Gender Effect for Vowels [a], [i], and [u] Vowel [a]

Symbol

Unit

CA

AA

I

Vowel [i] C

Fundamental frequency information measurements F0 Hz mf m>f m>f m>f Fhi Hz m f

CA

AA

I

C

CA

AA

I

C

mf m
mf m
mf m
mf m
mf m
mf m
mf m
mf m
m>f m>f m>f m>f m>f m>f

m>f

m>f

m>f

m
m
Short-term and long-term frequency perturbation Jita ␮s m>f m>f Jitt % RAP % PPQ % sPPQ % m>f % m>f vF0 Short-term and long-term amplitude perturbation ShdB dB Shim % APQ % sAPQ % vAm % m
Vowel [u]

m
m>f m
m
m>f m>f m>f

mf

m
m
Voice break–related measurements DVB % NVB Subharmonic components–related measurements DSH % NSH Voice irregularity related–measurements DUV % NUV Noise-related measurements NHR m>f VTI m>f SPI m>f Tremor measurements FTRI % m>f ATRI % Fftr Hz m>f Fatr Hz *Statistically

m>f

m>f

m>f

m>f

m>f

m>f

m>f

m>f m>f

m>f

m
significant findings indicated by culture, race, and MDVP vocal parameters.

Abbreviations: AA, African American; C, Chinese; CA, Caucasian; I, Indian.

Journal of Voice, Vol. 15, No. 2, 2001

m>f m>f mf m>f

m>f

MULTIMODAL STANDARDIZATION OF VOICE AMONG FOUR MULTICULTURAL POPULATIONS 97.33, P ≤ 0.0001), Flo (F[1, 28] = 110.99, P ≤ 0.0001) and STD (F[1, 28] = 9.45, P ≤ 0.0047). The group mean of African-American males was significantly higher than that of African-American females for the parameter T0 (F[1, 28] = 57.68, P ≤ 0.0001). For Indian subjects, the group means of males were significantly lower than that of females for the parameters F0 (F[1, 27] = 153.14, P ≤ 0.0001), Fhi (F[1, 27] = 84.37, P ≤ 0.0001), Flo (F[1, 27] = 196.91, P ≤ 0.0001) and STD (F[1, 27] = 5.42, P ≤ 0.03). The group mean of Indian males was significantly higher than that of Indian females for the parameter T0 (F[1, 27] = 514.06, P ≤ 0.0001). For Chinese subjects, the group means of males were significantly lower than that of females for the parameters F0 (F[1, 28] = 158.83, P ≤ 0.0001), Fhi (F[1, 28] = 64.19, P ≤ 0.0001), Flo (F[1, 28] = 67.76, P ≤ 0.0001) and STD (F[1, 28] = 14.84, P ≤ 0.0006). The group mean of Chinese males was significantly higher than that of Chinese females for the parameter T0 (F[1, 28] = 53.68, P ≤ 0.0001). No significant differences between males and females among African-American, Indian, and Chinese groups were observed for the parameter PFR. Short-term and long-term frequency perturbation measurements. For the main effect gender, the following significant differences were observed between the group means of males and females by culture and race for the parameters related to frequency perturbation measurements for the [a] vowel. For Caucasian subjects, the group means of males were significantly higher than that of females for the parameters Jita (F[1, 28] = 91.05, P ≤ 0.0001) and vF0 (F[1, 28] = 6.10, P ≤ 0.02). No significant differences between Caucasian males and females were observed for the parameters Jitt, RAP, PPQ, and sPPQ. For African-American subjects, the group means of males were significantly higher than that of females for the parameters Jita (F[1, 28] = 5.82, P ≤ 0.02) and sPPQ (F[1, 28] = 5.38, P ≤ 0.03). No significant differences between African-American males and females were observed for the parameters Jitt, RAP, PPQ, and vFo. For both Indian and Chinese groups, no significant differences for the main effect gender were observed for all six frequency perturbation parameters (Jita, Jitt, RAP, PPQ, sPPQ, and vFo).

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Short-term and long-term amplitude perturbation measurements. With respect to the five parameters related to amplitude perturbation measurements, no significant differences for the main effect gender were observed between male and female subjects regardless of culture and race for all five parameters (ShdB, Shim, APQ, sAPQ, vAm) during vowel [a] prolongation with the following exception. A significant difference was observed between Chinese males and females for the long-term amplitude perturbation parameter vAm. The group mean of Chinese males was significantly lower than that of Chinese females for this parameter (F[1, 28] = 10.94, P ≤ 0.003). Measurements related to voice breaks, subharmonic components, voice irregularity, noise, and tremor. One way analysis of variance statistics were not applied to parameters related to voice breaks (DVB, NVB), subharmonic components (DSH, NSH), and voice irregularity (DUV, NUV) for reasons previously stated. For noise-related measurements (NHR, VTI, and SPI) no significant differences for the main effect gender were observed among Caucasian and Chinese groups for all three of these parameters. For AfricanAmerican subjects, the group means of males were significantly higher than that of females for the parameters NHR (F[1, 28] = 22.80, P ≤ 0.0001), VTI (F[1, 28] = 4.11, P ≤ 0.05), and SPI(F[1, 28] = 4.17, P ≤ 0.05). For Indian subjects, the group means of males were significantly higher than that of females for the parameters NHR (F[1, 27] = 4.66, P ≤ 0.04) and SPI (F[1, 27] = 4.55, P ≤ 0.04). No significant differences between Indian males and females were observed for the VTI parameter. With respect to tremor related measurements (FTRI, ATRI, Fftr, Fatr), no significant differences for the main effect gender were observed among African-American and Chinese groups for all four parameters. For Caucasian subjects, the group means of males were significantly higher than that of females for the parameters FTRI (F[1, 28] = 4.65, P ≤ 0.04) and Fftr (F[1, 26] = 4.55, P ≤ 0.04). No significant differences between Caucasian males and females were observed for the ATRI and Fatr parameters. For Indian subjects, the group mean of males was significantly higher than that of females for the parameter FTRI (F[1, 27] = 13.04, P ≤ 0.001). No significant differences between Indian males and females were observed for the ATRI, Fftr, and Fatr parameters. Journal of Voice, Vol. 15, No. 2, 2001

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Steady vowel [i] prolongation Fundamental frequency information measurements. The following significant differences were observed for the main effect gender by culture and race for the parameters related to fundamental frequency measurements during steady vowel [i] prolongation. For Caucasian subjects, the group means of males were significantly lower than that of females for the parameters F0 (F[1, 28] = 220.43, P ≤ 0.0001), Fhi (F[1, 28] = 261.12, P ≤ 0.0001), Flo (F[1, 28] = 197.73, P ≤ 0.0001) and STD (F[1, 28] = 10.81, P ≤ 0.0027). The group mean of Caucasian males was significantly higher than that of Caucasian females for the parameter T0 (F[1, 28] = 147.91, P ≤ 0.0001). For African-American subjects, the group means of males were significantly lower than that of females for the parameters F0 (F[1, 28] = 105.07, P ≤ 0.0001), Fhi (F[1, 28] = 95.20, P ≤ 0.0001), and Flo (F[1, 28] = 242.16, P ≤ 0.0001). The group mean of African-American males was significantly higher than that of African-American females for the parameter T0 (F[1, 28] = 55.12, P ≤ 0.0001). For Indian subjects, the group means of males were significantly lower than that of females for the parameters F0 (F[1, 28] = 159.85, P ≤ 0.0001), Fhi (F[1, 28] = 128.06, P ≤ 0.0001), and Flo (F[1, 28] = 206.69, P ≤ 0.0001). The group mean of Indian males was significantly higher than that of Indian females for the parameter T0 (F[1, 28] = 556.18, P ≤ 0.0001). For Chinese subjects, the group means of males were significantly lower than that of females for the parameters F0 (F[1, 28] = 114.39, P ≤ 0.0001), Fhi (F[1, 28] = 111.18, P ≤ 0.0001), Flo (F[1, 28] = 122.97, P ≤ 0.0001) and STD (F[1, 28] = 6.44, P ≤ 0.02). The group mean of Chinese males was significantly higher than that of Chinese females for the parameter T0 (F[1, 28] = 99.14, P ≤ 0.0001). No significant differences for the main effect gender were observed among African-American and Indian groups for the STD and PFR parameters. No significant differences for the main effect gender were observed among Caucasian and Chinese groups were for the PFR parameter. Short-term and long-term frequency perturbation measurements. Significant differences for the main effect gender were observed by culture and race for the following parameters related to frequency perturbation measurements during vowel [i] prolongation. Journal of Voice, Vol. 15, No. 2, 2001

For Caucasian subjects, no significant differences were observed between the group means of males and females for all six frequency perturbation measurements. For African-American subjects, the group means of males were significantly higher than that of females for all six parameters Jita (F[1, 28] = 25.46, P ≤ 0.0001), Jitt (F[1, 28] = 6.26, P ≤ 0.02), RAP (F[1, 28] = 5.49, P ≤ 0.03), PPQ (F[1, 28] = 7.32, P ≤ 0.01), sPPQ (F[1, 28] = 13.03, P ≤ 0.001), and vF0 (F[1, 28] = 5.35, P ≤ 0.03). For Indian subjects, the group means of males were significantly higher than that of females for two parameters Jita (F[1, 28] = 11.15, P ≤ 0.0001) and vF0 (F[1, 28] = 5.21, P ≤ 0.03). No significant differences for the main effect gender were observed among Indian subjects for the parameters Jitt, RAP, and PPQ. For Chinese subjects, a significant difference was observed between the group means of males and females for only one frequency perturbation parameter, whereby the group mean of Chinese males was significantly higher than that of Chinese females for Jita (F[1, 28] = 4.36, P ≤ 0.05). No significant differences for the main effect gender were observed between Chinese males and Chinese females for five of the six frequency perturbation parameters (Jitt, RAP, PPQ, sPPQ, vF0). Short-term and long-term amplitude perturbation measurements. With respect to the five parameters related to amplitude perturbation measurements, significant differences were observed for the main effect gender by culture and race for some parameters during vowel [i] prolongation. For Caucasian subjects, the group means of males were significantly lower than that of females for the parameters ShdB (F[1, 28] = 47.63, P ≤ 0.0001), Shim (F[1, 28] = 49.41, P ≤ 0.0001), and APQ (F[1, 28] = 22.06, P ≤ 0.0001). No significant differences were observed between Caucasian males and their female counterparts for two parameters sAPQ and vAm. For African-American subjects, the group means of males were significantly lower than that of females for two parameters ShdB (F[1, 28] = 5.16, P ≤ 0.03) and Shim (F[1, 28] = 5.13, P ≤ 0.03). For Indian subjects, the group means of males were significantly lower than that of females for the parameters ShdB (F[1, 28] = 6.23, P ≤ 0.02) and Shim (F[1, 28] = 6.04, P ≤ 0.02). No significant differences for the main effect gender were observed among African-

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American and Indian groups for the parameters APQ, sAPQ, and vAm. For Chinese subjects, the group means of males were significantly lower than that of females for four parameters ShdB (F[1, 28] = 13.91, P ≤ 0.0001), Shim(F[1, 28] = 13.98, P ≤ 0.0001), APQ (F[1, 28] = 9.31, P ≤ 0.005), and vAm (F[1, 28] = 5.09, P ≤ 0.03). No significant differences were observed between Chinese males and their female counterparts for the parameter sAPQ.

For these cultural and racial groups, the group means of male subjects were significantly higher than that of their female counterparts for the FTRI parameter (African-American: F[1, 27] = 4.91, P ≤ 0.04; Indian: F[1, 26] = 8.97, P ≤ 0.0006; Chinese: F[1, 25] = 20.86, P ≤ 0.0001). No significant differences for the main effect gender were observed among AfricanAmerican, Indian, and Chinese groups for the parameters Fftr, Fatr, and ATRI.

Measurements related to voice breaks, subharmonic components, voice irregularity, noise, and tremor. One-way ANOVA statistics were not applied for parameters related to voice breaks (DVB, NVB), subharmonic components (DSH, NSH), and voice irregularity (DUV, NUV) for similar reasons previously stated. For noise-related measurements (NHR, VTI, and SPI), no significant differences for the main effect gender were observed between the group means of males and females among Chinese subjects for all three parameters. For Caucasian subjects, the group mean of males was significantly higher than that of females for the NHR parameter (F[1, 28] = 6.23, P ≤ 0.02), whereas the group mean of males was significantly lower than that of females for the SPI parameter (F[1, 28] = 4.11, P ≤ 0.05). For African-American subjects, the group mean of males was significantly higher than that of females for the NHR parameter (F[1, 28] = 8.79, P ≤ 0.01). No significant differences were observed between African-American males and their female counterparts for the VTI and SPI parameters. For Indian subjects, the group means of males were significantly higher than that of females for the parameters NHR (F[1, 28] = 18.35, P ≤ 0.0002) and SPI (F[1, 28] = 8.22, P ≤ 0.008). No significant difference for the main effect gender was observed among Caucasian and Indian groups for the VTI parameter. With respect to tremor-related measurements (FTRI, ATRI, Fftr, and Fatr), the group mean of Caucasian males was significantly lower than that of Caucasian females for the ATRI parameter (F[1, 19] = 5.82, P ≤ 0.03). No significant differences were observed between Caucasian males and their female counterparts for the FTRI, Fftr, and Fatr parameters. For the main effect gender among African-American, Indian, and Chinese groups, only one tremor related parameter (FTRI) was statistically significant.

Steady vowel [u] prolongation Fundamental frequency information measurements. The following significant differences were observed for the main effect gender by culture and race for parameters related to fundamental frequency measurements during steady vowel [u] prolongation. For Caucasian subjects, the group means of males were significantly lower than that of females for the parameters F0 (F[1, 28] = 204.49, P ≤ 0.0001) Fhi (F[1, 28] = 192.25, P ≤ 0.0001), Flo (F[1, 28] = 205.67, P ≤ 0.0001), and STD (F[1, 28] = 24.76, P ≤ 0.0001). The group mean of Caucasian males was significantly higher than that of their female counterparts for the parameter T0 (F[1, 28] = 212.91, P ≤ 0.0001). For African-American subjects, the group means of males were significantly lower than that of females for the parameters F0 (F[1, 28] = 78.64, P ≤ 0.0001), Fhi (F[1, 28] = 84.25, P ≤ 0.0001), Flo(F[1, 28] = 98.05, P ≤ 0.0001), and STD (F[1, 28] = 5.00, P ≤ 0.03). The group mean of African-American males was significantly higher than that of their female counterparts for the parameter T0 (F[1, 28] = 46.35, P ≤ 0.0001). For Indian subjects, the group means of males were significantly lower than that of females for the parameters F0 (F[1, 28] = 173.68, P ≤ 0.0001), Fhi (F[1, 28] = 161.84, P ≤ 0.0001), Flo (F[1, 28] = 173.48, P ≤ 0.0001), and STD (F[1, 28] = 10.59, P ≤ 0.003). The group mean of Indian males was significantly higher than that of their female counterparts for the parameter T0 (F[1, 28] = 509.95, P ≤ 0.0001). For Chinese subjects, the group means of males were significantly lower than that of females for the parameters F0 (F[1, 28] = 121.23, P ≤ .0001), Fhi (F[1, 28] = 122.46, P ≤ 0.0001), Flo (F[1, 28] = 122.75, P ≤ 0.0001), and STD (F[1, 28] = 19.29, P ≤ 0.02). The group mean of Chinese males was significantly higher than that of their feJournal of Voice, Vol. 15, No. 2, 2001

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male counterparts for the parameter T0 (F[1, 28] = 98.43, P ≤ 0.0001). Short-term and longterm frequency perturbation measurements. With respect to the six parameters related to frequency perturbation measurements, no significant differences for the main effect gender were observed among African-American and Chinese groups for the [u] vowel. For Caucasian subjects, the group means of males were significantly lower than that of females for three (Jita, RAP, PPQ) of the six (Jita, Jitt, RAP, PPQ, SPPQ, vF0) frequency perturbation parameters Jitt (F[1, 28] = 11.26, P ≤ 0.002), RAP (F[1, 28] = 12.61, P ≤ 0.0001), and PPQ (F[1, 28] = 11.17, P ≤ 0.002). No significant differences were observed between the group means of Caucasian males and their female counterparts for the parameters Jita, sPPQ, and vF0. For Indian subjects, the group mean of males was significantly higher than that of females for one parameter Jita (F[1, 28] = 10.31, P ≤ 0.003). No significant differences for the main effect gender were observed among Indian subjects for the frequency perturbation parameters Jitt, RAP, sPPQ, PPQ, and vF0. Short-term and long-term amplitude perturbation measurements. With respect to the five parameters related to amplitude perturbation measurements (ShdB, Shim, APQ, sAPQ, vAM), significant differences for the main effect gender were observed for some parameters among African-American, Indian, and Chinese groups for the [u] vowel. For Caucasian subjects, no significant differences for the main effect gender were observed for all five amplitude perturbation measurements. For African-American subjects, the group means of males were significantly higher than that of females for the parameters Shim (F[1, 28] = 4.58, P ≤ 0.04), APQ (F[1, 28] = 4.58, P ≤ 0.04), and sAPQ (F[1, 28] = 8.43, P ≤ 0.01). No significant differences were observed between African-American males and their female counterparts for two parameters: ShdB and vAm. For Indian subjects, the group mean of males was significantly higher than that of females for the parameter sAPQ (F[1, 28] = 6.03, P ≤ 0.02). No significant differences for the main effect gender were observed between Indian males and females for the parameters ShdB, Shim, APQ, and vAm. For Chinese subjects, Journal of Voice, Vol. 15, No. 2, 2001

the group means of males were significantly lower than that of females for four parameters ShdB (F[1, 28] = 11.18, P ≤ 0.002), Shim (F[1, 28] = 11.65, P ≤ 0.002), APQ (F[1, 28] = 5.89, P ≤ 0.02), and vAm (F[1, 28] = 10.97, P ≤ 0.003). No significant difference between Chinese males and their female counterparts was observed for the parameter sAPQ. Measurements related to voice breaks, subharmonic components, voice irregularity, noise, and tremor. For reasons previously stated, ANOVA statistics were not applied to parameters related to voice breaks (DVB, NVB), subharmonic components (DSH, NSH), and voice irregularity (DUV, NUV) for the [u] vowel. For noise-related measurements (NHR, VTI, and SPI), significant differences for the main effect gender were observed by culture and race for some parameters. For Caucasian subjects, the group mean of males was significantly lower than that of females for the SPI parameter (F[1, 28] = 4.66, P ≤ 0.04). No significant differences were observed between Caucasian males and their female counterparts for the NHR and VTI parameters. For African-American subjects, the group mean of males was significantly higher than that of females for the VTI parameter (F[1, 28] = 12.18, P ≤ 0.002). No significant differences were observed between AfricanAmerican males and their female counterparts for the NHR and SPI parameters. For Indian subjects, the group mean of males was significantly higher than that of females for the parameter NHR (F[1, 28] = 34.40, P ≤ 0.0001). For Chinese subjects, the group mean of males was significantly higher than that of females for the parameter NHR (F[1, 28] = 4.54, P ≤ 0.04) . No significant differences for the main effect gender were observed among Indian and Chinese groups for the VTI and SPI parameters. With respect to tremor-related measurements (FTRI, ATRI, Fftr, and Fatr), no significant differences for the main effect gender were observed among Caucasian, African-American, and Chinese groups for all four parameters. For Indian subjects, the group mean of males was significantly higher than that of their female counterparts for the ATRI parameter (F[1, 21] = 6.62, P ≤ 0.02). However, no significant differences between Indian males and Indian females were observed for the parameters FTRI, Fftr, and Fatr.

MULTIMODAL STANDARDIZATION OF VOICE AMONG FOUR MULTICULTURAL POPULATIONS DISCUSSION This experiment was designed to study the effects of culture and race on a variety of fundamental frequency and associated spectral measurements during steady prolongation of three isolated vowels while controlling for reliability of the acoustic measurement. A stratified random sample compromised of four homogeneous groups of male and female subjects were selected for study and matched on the basis of physiological variables (age, weight, and height) and cultural-linguistic markers (education, familial factors, native language, and dialect). The objectives of this study were to determine whether differences do indeed exist for the main effects “culture-race” and “gender” and to characterize subtle nuances in the acoustic spectra responsible for speaker identification possibly unique to a particular gender, culture, or race. The acquired acoustic data were not subjected to an inverse filtering process to preserve the influence of linguistic and dialectal markers on the natural resonating properties of the entire vocal tract. The test protocol and procedures as well as acoustic measurements obtained in this investigation were found to be reliable. The present findings suggest statistically significant group differences for the main effects of culture-race and gender pertaining to fundamental frequency measurements and spectral measurements for all three vowel tasks. Although numerous statistically significant differences were observed for the main effects of culture-race and gender, only the most compelling research findings will be discussed. For the main effect culture and race, Mandarin Chinese male speakers demonstrated significantly higher group mean fundamental frequencies than that of Caucasian and African-American male speakers of standard American English (SAE) and Hindi Indian male speakers with respect to average (F0), highest (Fhi), and lowest (Flo) fundamental frequency measurements for all extracted pitch periods during steady prolongation of the [a], [i], and [u] vowels. Moreover, Mandarin Chinese male speakers were observed with significantly lower group mean fundamental frequencies than that of three male control groups with respect to the average pitch period (T0) for all three vowel tasks. By definition, the average pitch period parameter (T0) is mathematically in-

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versely related to fundamental frequency (F0). Therefore, the higher the value of F0, the lower the To measurement.27 With respect to the spectral characteristics associated with each vowel prolongation for the main effect culture and race among male groups, Mandarin Chinese male speakers demonstrated significantly higher group mean amplitude perturbation than that of males belonging to the other three cultural and racial groups regarding both short-term (ShdB, Shim, APQ) and long-term (sAPQ) amplitude perturbation measurements during prolongation of the [i] vowel. However, Caucasian male speakers of SAE were observed with significantly lower group mean amplitude perturbation than that of AfricanAmerican, Indian, and Chinese male subjects regarding the same short-term (ShdB, Shim, APQ) and long-term (sAPQ) amplitude perturbation measurements during prolongation of the [i] vowel. Hindi Indian male speakers were observed with significantly higher group mean frequency perturbation than that of male subjects belonging to the other three cultural-racial groups regarding short-term (Jita, Jitt, RAP, PPQ) and long-term (sPPQ) frequency perturbation measurements during prolongation of the [u] vowel. Moreover, Hindi Indian male speakers demonstrated significantly higher group mean amplitude perturbation than that of Caucasian, African-American, and Chinese male subjects regarding short-term (ShdB, Shim, APQ) amplitude perturbation measurements during prolongation of the vowel [u]. Similar to their male counterparts, Mandarin Chinese female speakers demonstrated significantly higher group mean fundamental frequencies than that of Caucasian and African-American female speakers of SAE and Hindi Indian female speakers with respect to average (F0), highest (Fhi), and lowest (Flo) fundamental frequency measurements for all extracted pitch periods during steady prolongation of the [a], [i], and [u] vowels. Likewise, Mandarin Chinese female speakers were observed with significantly lower group mean fundamental frequencies than that of females belonging to the other three cultural-racial groups with respect to the average pitch period (T0) for all three vowel tasks. Consistent with their male counterparts with respect to spectral characteristics for the main effect of culture and race among female groups, Mandarin Chinese Journal of Voice, Vol. 15, No. 2, 2001

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female speakers were also observed with significantly higher group mean amplitude perturbation related to short-term (ShdB, Shim, APQ) and long-term (sAPQ, vAm) amplitude perturbation measurements during prolongation of the [a] and [i] vowels. Caucasian female speakers of SAE demonstrated significantly higher group mean amplitude perturbation than that of the three other female control groups related to short-term (ShdB, Shim, APQ) and longterm (sAPQ) amplitude perturbation measurements during prolongation of the [a] vowel. Similar to their male counterparts, Hindi Indian female speakers were observed with significantly higher group mean amplitude perturbation related to short-term (Shim, APQ) amplitude perturbation measurements during prolongation of the [i] and [u] vowels. For the main effect gender, male speakers regardless of culture and race demonstrated significantly lower group mean fundamental frequencies than that of their female counterparts with respect to average (F0), highest (Fhi), and lowest (Flo) fundamental frequency measurements for all extracted pitch periods during steady prolongation of the [a], [i], and [u] vowels. Moreover, male speakers regardless of culture and race were observed to have significantly higher group mean fundamental frequencies than that of their female counterparts with respect to the average pitch period (T0) for all three vowel tasks. With respect to associated spectral measurements regarding the [a] vowel task, Caucasian and African-American males were observed to have significantly higher group mean frequency perturbation than that of their female counterparts regarding short-term (Jita) and long-term (vF0, sPPQ) frequency perturbation measurements. Caucasian males also demonstrated significantly higher group mean tremor-related measurements (FTRI, Fftr) than their female counterparts during vowel [a] prolongation. African-American and Indian males were observed to have significantly higher group mean noise-related (NHR, SPI) measurements than their female counterparts and there was a significantly higher group mean voice turbulence index (VTI) among Indian subjects during vowel [a] prolongation. With respect to the vowel [i] prolongation, African-American males were observed to have significantly higher group mean frequency perturbation than their female counterparts for all short-term (Jita, Journal of Voice, Vol. 15, No. 2, 2001

Jitt, RAP, PPQ) and long-term (sPPQ, vF0) frequency perturbation measurements provided by the MDVP instrumentation. Likewise, Indian and Chinese males demonstrated significantly higher group mean frequency perturbation than their female counterparts with respect to absolute jitter (Jita) for the [i] vowel. Regardless of culture and race, male subjects demonstrated significantly lower group mean amplitude perturbation than their female counterparts related to short-term (ShdB, Shim, APQ) amplitude perturbation measurements during prolongation of the [i] vowel. In addition, Caucasian, African-American, and Indian males were observed to have significantly higher group mean noise-related measurements than their female counterparts regarding the noise-to-harmonics ratio (NHR) for the [i] vowel. With respect to tremor-related measurements, African-American, Indian, and Chinese males demonstrated significantly higher group means than their female counterparts regarding the tremor intensity index measurement (FTRI). During prolongation of the [u] vowel, Caucasian males were observed with significantly lower group mean frequency perturbation than that of their females counterparts regarding short-term (Jitt, RAP, PPQ) frequency perturbation measurements. However, Indian males demonstrated significantly higher group means than that of their female counterparts regarding absolute jitter (Jita) for the [u] vowel. With respect to amplitude perturbation measurements, African-American males were observed to have significantly higher group means than their female counterparts related to short-term (Shim, APQ, sAPQ) amplitude perturbation measurements during the vowel [u] prolongation. Chinese males demonstrated significantly lower group mean amplitude perturbation than that of their female counterparts regarding short-term (ShdB, Shim, APQ) and longterm (vAm) amplitude perturbation measurements for the [u] vowel. Compared to their female counterparts regarding noise-related measurements, African-American males demonstrated a significantly higher group mean voice turbulence index (VTI) or relative energy of high-frequency noise whereas Indian and Chinese males demonstrated significantly higher group means than their female counterparts with respect to noise-to-harmonics ratio (NHR) for the [u] vowel.

MULTIMODAL STANDARDIZATION OF VOICE AMONG FOUR MULTICULTURAL POPULATIONS CONCLUSION The present findings suggest that significant differences do exist with respect to fundamental frequency and associated acoustic spectra for three nonspeech tasks among four homogeneous groups of males and females controlled on the basis of physiological, linguistic, and dialectal variables for the main effect of culture-race and gender. Mandarin Chinese male and female speakers produced each vowel task with significantly higher fundamental frequencies than their male and female counterparts belonging to the other three cultural and racial groups. Moreover, Chinese male and female speakers evidenced significantly higher short-term and long-term amplitude perturbation for most vowel tasks. Likewise, Caucasian male and female speakers of SAE demonstrated lower fundamental frequencies and significantly lower amplitude perturbation for the [i] and [a] vowel tasks, respectively. As expected for the main effect gender, male subjects regardless of culture and race evidenced significantly lower fundamental frequencies for all three vowel tasks compared to their female counterparts per culture and race. Likewise, male subjects evidenced lower amplitude perturbation for the [i] and [u] vowel tasks that their female cultural and racial counterparts. However, male subjects demonstrated significantly greater frequency perturbation, noise, and tremor-related acoustic spectra for some vowel tasks compared to their female culture and racial counterparts. Several investigators have identified variables that influence the dynamics of phonation and its associated spectral qualities.28-34 The physical measures of fundamental frequency (F0) and vocal register are highly dependent on vocal fold length, density of the vocal fold tissue, and associated tension of the vibrating vocal folds. Moreover, phonation is dependent on the aerodynamic properties of the vocal tract whereby translaryngeal pressure determines the difference between subglottal and supraglottal pressure acting on the surfaces above and below the vocal folds.34 Subglottal air pressure significantly influences one’s ability to control pitch. However, the displacement of the vocal folds during phonation is dependent upon the degree of subglottal air pressure and length of the vocal folds. Therefore, to maintain constant anteriorposterior glottal length, greater subglottal air pressure

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is needed to displace the vocal folds laterally thus, facilitating greater maximum stretch of the vocal folds.34 Greater maximum stretch of the vocal folds facilitates higher effective tension and higher fundamental frequency. Moreover, pitch control and inflectional changes are influenced biomechanically and on a neuromuscular level by contraction of the cricothyroid and vocalis (thyroarytenoid) muscles as well as subglottal air pressures.31-34 Vocal quality variations at the glottal level are also affected by the degree of vocal fold approximation, or adduction, and aperiodicities in the acoustic signal. Titze33 has identified physiological and acoustic differences that account for gender variations, including membranous length of the vocal folds, mean airflow, sound power, glottal efficiency, amplitude of vibration, and overall size and shape of the larynx. The current findings are consistent with empirical data reported by the authors with respect to formant frequencies for the [a], [i], and [u] vowels whereby statistically significant differences were observed on the basis of culture-race and gender for this sample population.35 A follow-up investigation will explore fundamental frequency and spectral characteristics of speech tasks performed in English and subjects’ native languages. In addition, a variety of motor speech tasks, such as speaking rate and alternate motion rates, will be addressed to enumerate differences as well as similarities responsible for speaker identification among these four culturally and linguistically diverse sample populations. Acknowledgments: This research was supported by University of Massachusetts grant FRG 103247 and American Speech Language Hearing Association Multicultural Project 98A1472. REFERENCES 1. Titze IE. Workshop on Acoustic Voice Analysis. Summary Statement. Iowa City, IA: National Center for Voice and Speech. Wendell Johnson Speech & Hearing Center, University of Iowa; 1995. 2. Aronson A. Clinical Voice Disorders. New York, NY: Thieme; 1990. 3. Hollien H, Malcik E. Adolescent voice change in southern negro males. Speech Monogr. 1962;29:53-58. 4. Hollien H, Malcik E, Hollien B. Adolescent voice change in southern white males. Speech Monogr. 1965;32:87-89. 5. Hollien H, Malcik E. Evaluation of cross sectional studies of adolescent voice change in males. Speech Monogr. 1967:34: 80-84.

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6. Majewski W, Hollien H, Zalewski J. Speaking fundamental frequency of Polish adult males. Phonetica. 1972;25:11925. 7. Hudson A, Holbrook A. A study of the reading fundamental frequency of young black adults. J Speech Lang Res. 1981; 24:197-201. 8. Hudson A, Holbrook A. Fundamental frequency characteristics of young black adults: spontaneous speaking and oral reading. J Speech Lang Res. 1982;25:25-28. 9. Steinsaper C, Forner L, Stemple J. Voice characteristics among black and white children: Do differences exist? Cited in Walton JH, Orlikoff RF. Speaker race identification from acoustic cues in the vocal signal. J Speech Hear Res. 1994;37:738-745. 10. Nittrouer S, McGowan RS, Milenkovic PH, Beehler D. Acoustic measurements of men’s and women’s voice: a study of context effects and covariation. J Speech Hear Res. 1990;33:761-775. 11. Wheat MC, Hudson AI. Spontaneous speaking fundamental frequency of 6 year old black children. J Speech Hear Res. 1988;31:723-725. 12. Mayo R, Manning WH. Vocal tract characteristics of African-American and European-American adult males. Tex J Audiol Speech Pathol. 1994;20:33-36. 13. Walton JH, Orlikoff RF. Speaker race identification from acoustic cues in the vocal signal. J Speech Hear Res. 1994;37:738-745. 14. Mayo R, Grant WC. Fundamental frequency, perturbation, and vocal tract resonance characteristics of African-American and white American males. J Natl Black Assoc SpeechLang Hear. 1995;17:32-38. 15. Trent SA. Vocal quality: listener identification of African American versus Caucasian speakers. J Acoust Soc Am. 1995;98: 29-36. 16. Awan SN, Mueller PB. Speaking fundamental frequency characteristics of white, African American and Hispanic kindergartners. J Speech Hearing Res. 1996;39:573-577. 17. Xue, S. Effects of aging and ethinicity on selected vocal parameters: building a clinical comparative platform. Athens, OH: Ohio University (unpublished study). 18. Sapienza C. Aerodynamic and acoustic characteristics of the adult African American voice. J Voice. 1997;11:410-416. 19. Abu-Al-Makarem A, Petrosino L. Speaking fundamental frequency of young adult Arabic men (unpublished study). Presentation at the American Speech Language Hearing Association. San Antonio, Tex, November, 1998.

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20. Sonner-Ward H, Erickson M. Acoustic characteristics of Latin-American and European-American male adults (unpublished study). Presentation at the American Speech Language Hearing Association. San Antonio, Tex, 1998. 21. Lass NJ, Tecca JE, Mancuso RA, Black WI. The effect of phonetic complexity on speaker race and sex identifications. J Phonet. 1979;7:105-118. 22. Peterson GE, Barney HL. Control methods used in a study of vowels. J Acoust Soc Am. 1952; 24:175-184. 23. Bricker PD, Pruzanski S. Effects of stimulus content and duration on talker identification. J Acoust Soc Am. 1966;40:1442-1449. 24. Assmann PF, Neary TM, Hogan JT. Vowel identification: orthographic, perceptual, and acoustic aspects. J Acoust Soc Am. 1982;71:975-989. 25. Neary TM, Assmann PF. Modeling the role of inherent spectral change in vowel identification. J Acoust Soc Am. 1986;80:1297-1307. 26. Duffy JR. Motor Speech Disorders: Substrates, Differential Diagnosis, Management. St. Louis, MO: Mosby, 1995. 27. Kay Elemetrics. Multidimensional Voice Program (MDVP) Model 4305: Operations Manual, Issue A. Lincoln Park, NJ, 1993. 28. Hollien H, Curtis F. Vocal pitch variation related to changes in vocal fold length. J Speech Hear Res. 1960;3:150-156. 29. Hollien H, Moore P. Measurements of the vocal folds during changes in pitch. J Speech Hear Res. 1960;3:157-165. 30. Hollien H. A laminagraphic study of vocal pitch. J Speech Hear Res. 1960;3:361-371. 31. Sundberg J, Gauffin J. Waveform and spectrum of the glottal voice source. In: Lindblom B, Ohman, S, eds. Frontiers of Speech Communication Research. New York, NY: Academic Press, 1979. 32. Gauffin J, Sundberg J. Spectral correlates of glottal voice source waveform characteristics. J Speech Hear Res. 1989; 32:556-565. 33. Titze I. Physiologic and acoustic differences between male and female voices. J Acoust Soc Am. 1989;85;1699-1707. 34. Scherer RC. Physiology of phonation: a review of basic mechanics. In: Ford CN, Bless DM, eds. Phonosurgery Assessment and Surgical Management of Voice Disorders. New York, NY: Raven, 1991: 77–93. 35. Andrianopoulos MV, Darrow KN, Chen J. Multimodal standardization of voice among four multicultural populations: formant structures. J Voice. In press.

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APPENDIX. Description of Acoustic Parameters Calculated by MDVP MDVP Measurable Parameters Symbol

Unit

Description

Fundamental frequency information measurements F0 Hz Average fundamental frequency T0 ms Average pitch period Fhi Hz Highest fundamental frequency Flo Hz Lowest fundamental frequency STD Hz Standard deviation of F0 within analyzed voice sample PFR Semitones Phonatory fundamental frequency range between highest and lowest F0 Short-term and long-term frequency perturbation measurements Jita µs Absolute jitter; cycle-to-cycle frequency perturbation Jitt % Jitter percent; cycle-to-cycle frequency perturbation RAP % Relative average perturbation; short-term over 3 cycles PPQ % Pitch period perturbation quotient; short-term over 5 cycles sPPQ % Smoothed pitch period perturbation quotient; long-term over 55 cycles vF0 % Fundamental frequency variation coefficient; ratio of STD/F0 Short-term and long-term amplitude perturbation measurements ShdB dB Absolute shimmer; cycle-to-cycle amplitude perturbation Shim % Shimmer percent; cycle-to-cycle amplitude perturbation APQ % Amplitude perturbation quotient; short-term over 11 cycles sAPQ % Smoothed amplitude perturbation quotient; long-term over 55 cycles vAm % Peak amplitude variation coefficient; SD of cycle-to-cycle perturbation Voice break–related measurements DVB % Degree of voice breaks; ratio of the length of voice breaks of total sample NVB Number of voice breaks Subharmonic components–related measurments DSH % Degree of subharmonics; ratio of subharmonic to F0 components in sample NSH Number of subharmonics Voice irregularity–related measurements DUV % Degree of voiceless segments; ratio of unvoiced segments in total sample NUV Number of unvoiced segments Noise-related measurements NHR % VTI SPI Tremor measurements FTRI % ATRI

%

Fftr Fatr

Hz Hz

Noise-to-harmonics ratio; ratio of inharmonic energy in 1500-4500 Hz range to harmonic spectral energy in 70-4500 Hz range Voice turbulence index; ratio of inharmonic energy in 2800-5800 Hz range to harmonic spectral energy in 70-4500 Hz range Soft phonation index; ratio of harmonic energy in 70-1600 Hz range to harmonic energy in 1600-4500 Hz range F0 tremor intensity index; ratio of low-frequency F0 tremor to the total frequency magnitude of analyzed voice sample Amplitude tremor intensity index; ratio of low-frequency amplitude tremor to the total amplitude of the analyzed voice sample Fundamental frequency tremor frequency Amplitude tremor frequency

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