Effects on Voice Fundamental Frequency and Satisfaction with Voice in Trans Men during Testosterone Treatment—A Longitudinal Study

ARTICLE IN PRESS Effects on Voice Fundamental Frequency and Satisfaction with Voice in Trans Men during Testosterone Treatment—A Longitudinal Study *,†Ulrika Nygren, ‡,§Agneta Nordenskjöld, ¶,**Stefan Arver, and *,†Maria Södersten, *†‡§¶**Stockholm, Sweden Summary: Objectives. To investigate effects of testosterone treatment regarding voice virilization, voice problems, and voice satisfaction in transsexual female-to-male individuals, referred to as trans men. Study Design. Longitudinal. Methods. Fifty trans men, diagnosed with transsexualism, 18–64 years, met the inclusion criteria. Voice data before treatment and after 3, 6, or 12 months were available from 49 participants, and for 28 participants also after 18 and/or 24 months of treatment. Digital audio recordings of speech range profiles and voice range profiles were carried out in a sound-treated booth following clinical routines. Acoustic analyses of fundamental frequency (F0) and sound pressure level were made. Endocrine data and answers from questionnaires concerning voice function and voice problems were collected from medical records. Results. Mean F0 and mode F0 of the habitual voice decreased significantly after 3 months, 6 months, and up to 12 months, when group data were congruent with reference data for males. Mean F0 was 125 Hz after 12 months with a large interindividual variation. Sound pressure level values did not change significantly. Voice satisfaction correlated with lower F0 values. Twenty-four percent of the participants reported voice symptoms, for example, vocal instability and fatigue, and had received voice therapy. F0 values did not correlate with androgen levels. Conclusions. Most trans men developed a male voice and were satisfied. However, it is important to detect the substantial group of trans men with voice problems and with insufficient voice virilization and who may need voice therapy. Therefore, we recommend systematic voice assessments during testosterone treatment. Key Words: transsexualism–female-to-male transsexual persons–androgens–voice therapy–transmasculine.

INTRODUCTION Individuals may experience gender incongruence—a discrepancy between their gender identity and their sex assigned at birth and their bodily appearance. If gender incongruence causes distress, the individual may receive the diagnosis transsexualism (TS), (International Classification of Diseases, ICD-10: F64.0), fulfilling the criteria “a desire to live and be accepted as a member of the opposite sex, usually accompanied by a sense of discomfort with, or inappropriateness of, one’s anatomic sex, and a wish to have surgery and hormonal treatment to make one’s body as congruent as possible with one’s preferred sex.”1 The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, DSM-5 introduces the diagnosis gender dysphoria,2 which widens the scope of gender dysphoria. Over time, various terms have been used to describe the condition, such as transsexual, gender identity disorder, gender dysphoria, or transgender. For individuals who have been assigned a female sex at birth and Accepted for publication October 23, 2015. From the *Karolinska Institutet, Department of Clinical Science, Intervention and Technology, Division of Speech and Language Pathology, SE-171 77 Stockholm, Sweden; †Karolinska University Hospital, Department of Speech and Language Pathology, SE171 76 Stockholm, Sweden; ‡Karolinska Institutet, Department of Women’s and Children’s Health and Center of Molecular Medicine, SE-171 77 Stockholm, Sweden; §Karolinska University Hospital, Department of Paediatric Surgery, Astrid Lindgren Children’s Hospital, SE-171 76 Stockholm, Sweden; ¶Karolinska Institutet, Department of Medicine/ Huddinge, SE-171 77 Stockholm, Sweden; and the **Karolinska University Hospital, Centre for Andrology and Sexual Medicine, SE-171 76 Stockholm, Sweden. Address correspondence and reprint requests to Ulrika Nygren, Department of Speech and Language Pathology, B69, Karolinska University Hospital, SE-141 86 Stockholm, Sweden. E-mail address: [email protected] Journal of Voice, Vol. ■■, No. ■■, pp. ■■-■■ 0892-1997 © 2015 The Voice Foundation. Published by Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.jvoice.2015.10.016

experience gender incongruence causing distress, terms such as female-to-male (FtM) transsexuals, transsexual men, and transmasculine have been used,3,4 and more lately “trans men,”5 which we have chosen to use in the present study. Individuals for whom the diagnosis of TS has been confirmed are offered surgical and medical help such as cross-sex hormones, surgery to alter chest and genital organs to alter phenotype, and also change of legal gender status.6,7 The incidence of applications for legal and surgical sex reassignment in Sweden between 1972 and 2010 has increased significantly for trans men; from 0.16 to 0.42/100,000/year. The sex ratio (trans men:trans women) was 1:1.66 during 1972 to 2010.6 In Sweden, approximately 30 trans men per year during 2010 to 2012 formally applied for change of legal status and surgical sex reassignment at the National Board of Health and Welfare. In 2013, the number of applications tripled to 90, and in 2014 the number had risen to 96. The later increment may reflect an accumulation of applicants who waited for the waiving of the castration requirement for gender change that happened mid-2013. Today, no surgical intervention is required to attain a new legal gender. In Sweden, both trans men and trans women are referred to endocrinologists and speech and language pathologists when the diagnosis of TS has been confirmed by the psychiatric gender team.8 Testosterone (T) treatment in trans men aims to induce and maintain virilization by consistent T maintenance of T levels within the normal male range (10–30 nmol/L).9 Some changes induced by T treatment are reversible and require life-long supplementation to maintain secondary sex characteristics, whereas others are irreversible, for example, voice change and clitoral growth.10,11 T treatment is administered with intramuscular depot

ARTICLE IN PRESS 2 injections or transdermally with T gels, although in some countries, oral T formulations and implantable pellets are available.11 Monitoring of T treatment in trans men includes assessments of proceeded T levels, which is also reflected by suppression of luteinizing hormone (LH) and increase in erythropoiesis (production of red blood cells), measured through levels of hemoglobin (Hb), which is assessed by determination of hematocrit or erythrocyte volume fraction (EVF). Sex hormone-binding globulin (SHBG), a binding protein that binds T and forms a nonactive T complex, thus can influence the actual fraction of T that is biologically active. EVF can be used as a surrogate marker for androgen exposure. Androgen receptor (AR) polymorphism (normal genetic variability) has been reported to influence AR responsiveness (sensitivity). In brief, receptors can be divided in more or less responsive receptors based on variation in gene structure of the first exon of the receptor. The number of cytosineadenine-guanine (CAG) repeats in the AR gene seems to affect the difference in receptor activity. Men with shorter CAG length therefore respond with larger increase in EVF (or Hb levels) than men with longer CAG length when exposed to similar levels of T.12 Side effects of androgen treatment are, for example, acne and excessive stimulation of erythropoiesis. Severe adverse reactions are rare if T levels are maintained in the normal male range.11 The main differences reported between male and female voices are that men’s voices have lower fundamental frequency (F0), higher sound pressure level (SPL), less breathy voice quality, approximately 20% lower formant frequencies, and smaller habitual and physiological voice range.13–16 It is important for most trans men to be recognized as male by others based on how their voice sound.17 In a longitudinal study by Van Borsel et al,18 the voice change was described in two patients (22 and 37 years) treated with intramuscular testosterone undecanoate (TU) depot injection for 12 and 13 months. The frequency range and the mean F0 (MF0) were measured while the patients were reading. MF0 decreased to 155 Hz and 132 Hz, respectively, and the largest change was evident after 4 months of treatment. Frequency range was reduced in both patients because of a loss of high frequencies that was not compensated by gain of low frequencies. Damrose19 reported voice data from a 33-year-old FtM before and after 16 months of treatment with 200 mg of T injected intramuscularly every 2 weeks. Laryngostroboscopy was performed, and MF0 of sustained /a:/ for 5 seconds was analyzed. MF0 decreased from 228.47 Hz before treatment to 112.74 Hz after 16 months of treatment. A marked decline in MF0 to 116.52 Hz occurred between the third and the fourth months of treatment. The laryngostroboscopy did not show any obvious morphological changes.19 According to Gooren,10 a deepening of the voice in FtM transsexuals occurs after 6–10 weeks of T treatment with intramuscular doses of 200–250 mg every 2 weeks. However, the author did not describe how the voice change was measured. In a recent controlled cross-sectional study, the voices and hormonal factors were examined in 38 FtM transsexual persons after long-term T treatment (9 months to 22 years) and in agematched male controls.20 The patient group did not differ

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significantly from the controls in terms of the acoustic voice variables median F0 and F0 variation. In 10% of the patients, however, the voice change was not sufficient. An insufficient pitch lowering was interpreted as being associated with diminished androgen sensitivity. Higher hematocrit and a longer CAG repeat in the AR gene were found in the cases with lowest pitched voices, in contrast to a series of other studies.12 Knowledge about voice change, voice characteristics, and voice problems during T treatment in trans men is insufficient.21 Some information has been presented in case reports, studies on small groups,17–19,22,23 and recently in a larger cross-sectional study based on 38 participants and age-matched controls.20 So far, no longitudinal study has been performed on a large group of trans men. The overall aim of this study was to examine voice changes during T treatment in trans men with the following questions addressed: To what extent and for how long does the voice F0 decrease? Is the voice SPL affected by androgen treatment? Are the patients satisfied with the voice changes? Is voice therapy needed? Is there a relationship between voice F0 and satisfaction with the voice, and androgen levels? METHOD Participants and materials All patients were referred to the Department of Speech and Language Pathology, Karolinska University Hospital, after the ICD-10 diagnosis of “transsexualism” F64.0 was confirmed by the psychiatric gender team at the Department of Psychiatry, Karolinska University Hospital.8 The present study includes longitudinal information from medical records and voice recordings between 2006 and 2014. The clinical routine was to assess the voice before start of T treatment and regularly after 3, 6, 12, 18, and 24 months of treatment. Voice assessment, including digital audio recordings of the voice, was carried out at every visit. The patients also performed self-ratings of voice function and voice problems. At each visit, they also received information about their voice, vocal hygiene, and recommendations on how to prevent vocal fatigue. A total of 104 trans men ≥18 years were referred for voice assessment during the years 2006–2013. For inclusion in the current study, accessible voice recordings before start of the T treatment and at least one recording during treatment were needed. Fifty-two patients were excluded because they had already started T treatment before the first visit. Two patients terminated T treatment, one because of side effects and one because of doubts regarding gender identity, and were excluded. Thus, the final number of participants who met the inclusion criteria was 50 (Table 1). The age of the participants at the start of T treatment is shown in Table 1. Ideally, the participants should have come for voice assessments after 3, 6, 12, 18, and 24 months of treatment; however, not all came to all visits or at the exact time. The recordings were divided into six groups (before treatment, and after 3, 6, 12, 18, and 24 months of treatment) with time ranges as shown in Table 1; 3 months (range 2–5 months), 6 months (range 5 months and 12 days to 10 months), 12 months (range 11–15 months), 18 months (range 16–21 months), and 24 months (range 22–36 months). Nine of the 50 participants

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TABLE 1. The number of voice recordings made for each of the four treatment groups before treatment (n = 50), and after 3, 6, 12, 18, and 24 months (time range) based on how many times the participants came for voice assessment 3 Months 6 Months 12 Months 18 Months 24 Months Before (22–36) (16–21) (11–15) (5–10) (2–5) Treatment n n n n n n

Treatment groups Intramuscular injection Transdermal administration Transdermal/intramuscular injection Adolescents: intramuscular injection Total

29 4 8 9 50

24 4 4 7 38

25 3 6 8 41

19 4 6 7 36

14 1 6 3 24

12 3 6 1 22

Mean Age (Range) 29 (19–64) 36 (22–47) 30 (22–46) 18 (18–19) 27 (18–64)

Notes: Mean age (years) and age range of the participants at the start of testosterone treatment is presented for each treatment group.

came to all five visits after starting T treatment, 19 of 50 came to four visits, 33 of 50 came to three visits, 49 of 50 came to two visits, and all the 50 participants came to one visit after starting T treatment. Twenty-one participants came to all three visits during the first year and 45 participants came to at least two of the three visits. There were 22 participants who did not come after the 12-month timepoint. A total of 211 recordings and completed questionnaires, out of a total maximum possible number of 300, were included for analysis. Missing data within each timepoint were 0% before treatment, 24% after 3 months, 18% after 6 months, 28% after 12 months, 52% after 18 months, and 58% after 24 months. For detailed information, see Appendix. Androgen treatment Four different treatment regiments were used as seen in Table 1, according to current guidelines.11 A majority of the participants (n = 29) were given intramuscular injections of TU, 1000 mg every 8–12 weeks. Four participants were treated with 1% transdermal hydroalcoholic T gel, 50 mg daily. Eight participants started with transdermal administration and switched to TU injections. Nine participants, labeled in Table 1 as “adolescents,” had been treated with gonadotropin-releasing hormone analog to stop pubertal development before initiation of androgen treatment at 18 years of age. Dosing of T in adolescents started at 18 years with either 75 mg or 125 mg T enanthate every fourth week with gradual increment to 250 mg/4 weeks. Dosing levels were maintained for 3 months before adjustment to a higher level.

Blood was sampled before start of T treatment and after 3 to 31 months of treatment for most of the participants. Blood was drawn in the later part of the injection interval or 2–4 h after gel application in patients on transdermal therapy. Endocrine data were collected from medical records, that is, information about start, type (intramuscular or transdermal T formula), doses, and frequency of T treatment, as well as serum (S)-T, S-LH, S-SHBG, blood-Hb, and blood-hematocrit (EVF). If blood was sampled more than once after 3 months of treatment, a mean value was calculated. Some values are missing because the data were not available in the medical records. All data from blood samples included in the study are presented in Table 2. Voice recordings and acoustic analyses Digital audio recordings of the participants’ habitual voice and physiological voice range were made in a sound-treated booth according to clinical routines at the Department of Speech and Language Pathology at Karolinska University Hospital. A phonetogram is a recording of a speech range profile (SRP) or a voice range profile (VRP), presented as two-dimensional images of the voice in terms of F0 and voice SPL, measured over time.24 The computer programs Soundswell and Phog (Neovius Data och Signalsystem AB, Lidingö, Sweden) and an electret microphone (Sennheiser MKE-2, Sennheiser, Wennebostel, Germany) mounted on a headset, placed at a distance 15 cm from the mouth, were used during the recordings. For analyses, SPL values were corrected for 30-cm mouth-to-microphone distance. All data included from the SRPs and VRPs are presented in Table 3. Some

TABLE 2. Endocrine parameters at follow-up after 3–24 months of testosterone treatment in comparison with values before treatment in the participants who were evaluated during treatment

T (nmol/L) LH (IU/L) SHBG (nmol/L) Hb (g/L) EVF

Before Treatment

n

Follow-up 3–24 Months

n

P Value

2.1 ± 1.9 7.2 ± 6.4 51 ± 20.4 135 ± 9.3 0.41 (0.4–0.42)

44 40 33 41 36

25.3 ± 11.9 2.9 ± 3.1 28 ± 11.9 151 ± 13.6 0.46 (0.45–0.47)

27 33 37 45 43

<0.001 0.019 <0.001 <0.001 <0.001

Notes: Data are presented as mean ± standard deviation except for EVF for which data are presented as median (the 25th and 75th percentiles). The number of participants for whom data were analyzed (n) before treatment and at follow-up is shown. P value results from Student paired t test. Abbreviations: B, blood; EVF, erythrocyte volume fraction; Hb, B-hemoglobin; LH, S-luteinizing hormone; S, serum; SHBG, S-sex hormone-binding globulin; T, S-testosterone.

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TABLE 3. Mean F0 (MF0), F0-mode, Leq, and area were measured from the speech range profile (SRP). The lowest F0 (Min F0), the highest F0 (Max F0), and the maximum sound pressure level in modal register (Max SPL) were measured from the voice range profile (VRP) for the 50 participants. Data are presented as mean, standard deviation (SD), range, median, and the 25th and 75th percentiles. The number of participants for whom data were analyzed (n) is shown for each variable before treatment and at 3, 6, and 12 months

SRP MF0 (Hz) Before treatment 3 months 6 months 12 months SRP F0-mode (Hz) Before treatment 3 months 6 months 12 months VRP Min F0 (Hz) Before treatment 3 months 6 months 12 months VRP Max F0 (Hz) Before treatment 3 months 6 months 12 months SRP Leq (dB 30 cm) Before treatment 3 months 6 months 12 months VRP Max SPL (dB 30 cm) Before treatment 3 months 6 months 12 months SRP area (ST × dB) Before treatment 3 months 6 months 12 months VRP area (ST × dB) Before treatment 3 months 6 months 12 months

n

Mean (SD)

Range

Median

25th, 75th Percentiles

50 38 41 36

192 (22.4) 155 (28.8) 134 (25.5) 125 (18.7)

147–242 95–200 93–192 89–170

190 155 129 127

185–198 146–165 126–142 119–132

50 38 41 36

178 (22.3) 146 (28.2) 127 (25.2) 117 (19.8)

144–226 86–202 84–182 82–164

176 150 124 116

171–184 137–155 119–135 110–124

49 38 39 36

130 (21.9) 103 (23.6) 86 (17.4) 79 (9.6)

98–185 62–156 65–147 62–98)

123 98 78 78

98–185 95–111 80–92 76–83

36 32 35 35

941 (255) 809 (199) 757 (234) 746 (191)

622–1661 415–1480 415–1661 415–1319

906 784 784 740

855–1027 737–881 676–837 680–812

49 33 39 34

70.5 (3.0) 70.8 (3.3) 70.7 (2.9) 70.8 (2.3)

64.5–78.3 62.7–76.2 64.0–77.8 65.4–75.8

69.7 71.5 70.3 70.9

69.6–71.4 69.7–72.0 69.8–71.6 70.0–71.6

45 38 39 36

95.7 (5.0) 95.6 (5.4) 95.9 (4.8) 96.7 (5.3)

87–106 83–103 83–103 80–107

96.0 96.5 97.0 97.0

94.2–97.2 93.8–97.4 94.3–97.4 94.9–98.5

49 33 39 34

123 (29.6) 121 (26.1) 115 (26.9) 122 (29.5)

64–190 81–179 69–173 63–209

120 118 116 120

114–132 112–130 106–124 112–132

42 34 37 35

1060 (287) 1037 (236) 1007 (291) 1158 (281)

536–1849 527–1559 394–1795 669–2081

1038 1045 1016 1126

971–1150 954–1119 910–1104 1061–1254

values are missing because of technical problems at the time of the recordings or not enough time to complete the VRP as indicated in Table 3. An SRP of habitual speaking voice was recorded during running speech. The participants read aloud a Swedish standard text of about 40 seconds’ duration and narrated a story from a series of six pictures. The following variables were collected using the analysis tools in Phog: MF0 and mode F0 (F0mode) in Hz, the equivalent continuous sound level (Leq) in dB, and the area in semitones × decibel (ST × dB). Registrations more

than one ST or 1 dB outside the connected area, and vocal fry were not included in the analysis (Figure 1A) according to the procedure described by Hallin et al.25 The reading and the narrating were analyzed together to obtain a natural voice sample.16,25 A VRP of the physiological range was recorded following the guidelines presented in Hallin et al.25 The participants performed a maximum VRP on sustained phonations and glissandi using the vowel /a:/. Recordings were made of phonation in soft voice for the lower contour in SPL to catch the lowest possible SPL, first at a comfortable pitch then with deceased pitch to reach

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A

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B

FIGURE 1. (A) Speech range profile for a participant before start of testosterone treatment. (B) Voice range profile (VRP) for a participant after 3 months of treatment. The x-axis shows the fundamental frequency in Hz and the y-axis shows the sound pressure level in dB, 15 cm. Registrations more than one semitone or 1 dB outside the connected area were not included in the analyses, and are marked in the figures with /. In the VRP, the arrows show the minimum F0 (Min F0), maximum F0 (Max F0), and maximum SPL (Max SPL). the lowest F0 possible, and then with increased pitch to reach the highest F0 possible. The same procedure was used for loud phonation to register the upper contour in SPL. It took approximately 20–30 minutes to record a VRP. The following variables were collected using the analysis tools in Phog: minimum F0 (Min F0), maximum F0 (Max F0) in falsetto register, the highest voice SPL (Max SPL) in dB in modal register, and the area in ST × dB. Registrations of vocal fry were not included (Figure 1B) in the analysis. Questionnaires The participants indicated the degree to which they agreed with statements about their voice function and voice problems related to virilization. The following statements were relevant for the present study: I am perceived as male when speaking on the phone; I am satisfied with my voice; I am worried that my voice will reveal my native sex; and I get tired in my throat/voice or hoarse when speaking. The questionnaire’s rating scale changed slightly over the years of data collection to get the questionnaire congruent with other voice clinics’ according to a Swedish national program.8 In the first version, it was a seven-point equalappearing interval scale, in which 1 corresponded to “Never” and 7 corresponded to “Always.” In the second version, a fivepoint scale was used in which 0 corresponded to “Never,” 1 to “Almost never,” 2 to “Sometimes,” 3 to “Almost always,” and 4 to “Always.” To compare the results from the questionnaires during the hormone treatment, the ratings from the five-point scale were converted to fit the seven-point scale: 0 on the fivepoint scale was converted to 1, 1 to 2.5, 2 to 4, 3 to 5.5, and 4 to 7. This transformation was possible because the seven-point scale lacked category names for the numbers in between the scale extremes. In the second version, the statements I am satisfied with my voice and I am perceived as male when speaking on the phone were formulated I am not satisfied with my voice and I am perceived as female when speaking on the phone. Thus, the answers were converted in the analyses to compare the results.

Voice therapy Information about whether participants had received voice therapy was collected from the medical records. The motivations for voice therapy were based on the patients’ subjective symptoms, that is, vocal fatigue, vocal instability, strain, hoarseness, problems projecting the voice, insufficient lowering of F0, and/or problems with the voice sounding too young. Ethical considerations The regional ethics board at Karolinska Institutet, Stockholm, approved the study (Dnr 2010/1829-31/3). Statistics Descriptive statistics expressed as means, medians, standard deviations, minimum and maximum values, and 25th and 75th percentiles were calculated for all variables. To compare the results from the present study with reference values from other studies, 95% confidence intervals were used. Longitudinal data from acoustic analyses and questionnaires were analyzed with a linear mixed model. The within-group factor “time” was divided into six fixed timepoints: before treatment, and after 3, 6, 12, 18, and 24 months of treatment. When the time effect was significant, multiple comparisons between different timepoints were performed with Bonferroni corrections of the P values. Androgen levels after at least 3 months of treatment were compared with levels before treatment using Student paired t tests. Spearman rank-order correlations were used to measure the association between F0 and self-ratings of the voice, and between F0 and androgen levels (after at least 3 months of treatment). Correlation coefficients were interpreted according to Colton,26 that is, 0 to 0.25 indicates little or no correlation, 0.25 to 0.50 a fair degree, 0.50 to 0.75 a moderate to good, and above 0.75 a very good to excellent correlation. All statistical analyses were made for the entire group of participants and for the group that received intramuscular injection; the other three treatment groups were not analyzed separately because of too few participants in

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B

C

FIGURE 2. Box plot diagram showing mean fundamental frequency (MF0) (A), F0-mode (B) from speech range profiles (SRP), and minimum (Min) F0 (C) from voice range profiles (VRP), for the entire group of participants (n = 50) before treatment, and after 3, 6, 12, 18, and 24 months. The asterisks indicate where statistically significant differences were found. **P < 0.005; ***P < 0.001. those groups. All statistical calculations of frequency values in Hz were confirmed by calculations in ST from a reference tone, using the formula 12 × LN(x/110)/LN(2). A P value <0.05 was considered statistically significant. SPSS Statistics 21.0 (SPSS Inc., Chicago, Illinois, USA) was used for all statistical analyses. RESULTS F0 A significant effect of time was demonstrated regarding MF0 (F(5,159) = 140, P < 0.001) and F0-mode (F(5,159) = 113, P < 0.001) from the speaking range, and also for Min F0 in the physiological range (F(5,158) = 99, P < 0.001). MF0 and F0mode, and Min F0 decreased significantly in the first 3 months, and between 3 and 6 months for the whole group of participants (n = 50). MF0 and F0-mode also decreased significantly between 6 and 12 months of treatment, with no further significant F0 lowering after 12 months (Figure 2A–C). Max F0 in the physiological range decreased significantly up to 3 months

of treatment with no further significant lowering. The mean value of MF0 was 192 Hz (interindividual range 147–242 Hz) before treatment, 155 Hz (interindividual range 95–200 Hz) after 3 months of treatment, and 125 Hz (interindividual range 89– 170 Hz) after 12 months of treatment (Table 3). Thus, the ranges in MF0 at 3, 6, and 12 months were considerable. Six participants still showed high MF0 values between 143 and 170 Hz at the latest recording; one of these had been given transdermal administration, four received TU injections, and one started with transdermal administration and switched to TU injections. These six participants’ values regarding F0-mode ranged from 128 to 164 Hz. Ten participants had rather low MF0 values, below 175 Hz, even before T treatment. These 10 participants’ MF0 at the final recording did not differ from that of the 40 participants who had MF0 higher than 175 Hz before treatment. The F0-mode decreased from 178 Hz before treatment to 146 Hz after 3 months, and to 117 Hz after 12 months but varied substantially between individuals (Table 3). The mean value of Min F0

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in the physiological range decreased from an initial value of 130 Hz to 79 Hz after 12 months, and Max F0 decreased from an initial mean value of 941 Hz to 746 Hz after 12 months (Table 3). SPL The equivalent contious sound level (Leq) did not change significantly during T treatment (70.5 dB before treatment and 70.8 dB after 12 months [Table 3] and 71.7 dB after 24 months). Max SPL in the modal register, measured from the VRP, also remained essentially unchanged (the mean value of Max SPL was 95.7 dB initially and 96.7 dB after 12 months [Table 3] and 96.7 dB after 24 months of treatment). Area measures No significant effects of time were demonstrated regarding SRP area or VRP area. The mean value for SRP area was 123 ST × dB before treatment, 115 ST × dB after 6 months, and 122 ST × dB after 12

7

months. The mean VRP area was 1060 ST × dB before treatment and 1158 ST × dB after 12 months (Table 3). F0 for the four treatment groups MF0 decreased significantly from 192 Hz (interindividual range 147–242) before treatment to 129 Hz (range 93–164) already after 6 months in the group treated with intramuscular injections (n = 29). No further significant lowering of MF0 and F0-mode occurred after 6 months for this group. For the other three treatment groups, MF0 and F0-mode lowered after 12 months, but statistical analyses were not performed because the groups were too small to be analyzed separately (Table 1). Self-ratings of voice function and satisfaction with voice Results from all participants are shown in Figure 3A–D. For the statements I am perceived as male when speaking on the phone and I am satisfied with my voice, the ratings had increased significantly both at 3 months, and between 3 and 6 months of

A

B

C

D

FIGURE 3. Box plot diagrams showing self-ratings for the entire group of participants (n = 50) before treatment, and after 3, 6, 12, 18, and 24 months. The statements participants were rating are presented above the diagrams. The ratings were given on a seven-point scale in which 1 corresponded to “never” and 7 corresponded to “always.” The asterisks indicate where a statistically significant difference was found. *P < 0.05, ***P ≤ 0.001.

ARTICLE IN PRESS 8 treatment as seen in Figure 3A and B, and for the statement I am perceived as male when speaking on the phone, the ratings had increased between 6 and 12 months. The ratings of the statement I am worried that my voice will reveal my native sex decreased significantly from before treatment to 6, 12, 18 and 24 months, respectively, and between 3 and 6 months (Figure 3C). The ratings showed a large variation up to 12 months and a smaller variation at 18 and 24 months. No significant changes were found for I get tired in my throat/voice or hoarse when speaking and the ratings varied considerably (Figure 3D). Voice therapy Twenty-four percent (12 of 50) of the participants had received voice therapy because of subjective voice problems such as vocal fatigue (nine of 12), vocal instability (five of 12), strained voice quality due to attempts to sound more low pitched (nine of 12), hoarseness (six of 12), insufficient lowering of the pitch (five of 12), difficulties projecting the voice (four of 12), and problems that the voice sounded too young for their chronological age (two of 12). The number of therapy sessions varied between 1 and 5, with a mean of 3.2. The voice therapy, for all these 12 patients, started after the commencement of T treatment. Androgen levels and related assessments Statistically significant increases in T levels and in EVF and Hb levels were found in comparison with pretreatment levels. The SHBG and LH levels decreased significantly compared with pretreatment levels (Table 2). Correlations between F0 and self-ratings of the voice, and between F0 and androgen levels (after at least 3 months of treatment) Negative moderate-to-good correlations were found between MF0, F0-mode and Min F0, and the statement I am satisfied with my voice (rs = −.70, rs = −.68, and rs = −.66, respectively); that is, lower F0 values correlated with greater satisfaction with the voice. A negative moderate-to-good correlation was also found between all F0 values and the statement I am perceived as male on the phone (rs = −.65, rs = −.63, and rs = −.52, respectively); that is, lower F0 values correlated with higher ratings regarding being perceived as male on the phone. No or little correlations were found between MF0, F0-mode and Min F0, and the answers to the statements I am worried that my voice will reveal my native sex and I get tired in my throat/voice or hoarse when speaking. There were no or little correlations between MF0, F0-mode and Min F0, and the androgen levels and related assessments (T, LH, SHBG, Hb, and EVF). DISCUSSION This is the first longitudinal study on voice changes during T treatment in a large group of trans men. The main novel findings were that group data for F0 values were in congruence with reference data for male speakers after 12 months of T treatment, with a large interindividual variation, that lower F0 values correlated with higher voice satisfaction and that a quarter of the participants had received voice therapy.

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One limitation of this clinical study was that participants did not come to all visits and not at the exact time according to the plan (before treatment, and after 3, 6, 12, 18, and 24 months of treatment). If all patients had come to all six voice assessments, a total of 300 recordings would have been available instead of the 211 collected. However, we could calculate the voice changes during treatment because data could be grouped according to time ranges (Table 1), even though the number of recordings differed between timepoints. The great variation in the number of voice recordings and variation in the timepoint for each visit prompted us to use a linear mixed model as the most appropriate statistical method for analyzing the voice change. Voice analyses The reference frequency for MF0 is 188 Hz in vocally healthy Swedish females,15 183 Hz in vocally healthy Australian females,16 123 Hz in vocally healthy Swedish males,25 and 110 Hz in vocally healthy Australian males.16 The reference frequency for median F0 is 109 Hz in trans men after 9 months to 22 years of T treatment.20 In our study, MF0 was 192 Hz before treatment started (95% CI between 185 and 198 Hz) and decreased to 155 Hz after 3 months of treatment (95% CI 146–165 Hz) and 125 Hz after 12 months of treatment (95% CI 119–132 Hz). MF0 at 12 months is in congruence with reference data for vocally healthy Swedish males.25 The final values of MF0 did not differ in participants who originally had low MF0 (≤175 Hz) and participants who had MF0 within reference values for vocally healthy Swedish females (≥175 Hz).15 The mean value of Min F0 in the physiological range before treatment was 130 Hz (95% CI 124– 136 Hz), which is slightly higher than reference data from vocally healthy Australian females (118 Hz).16 Min F0 declined to 86 Hz (95% CI 80–92 Hz) after 12 months, which is in congruence with reference data for vocally healthy Swedish males.25 The finding of the present study that MF0 decreased significantly during the first 3 months of treatment is in accordance with previous longitudinal case studies.19,22 Our results regarding F0 values after 12 months of treatment are also in accordance with those from the cross-sectional study by Cosyns et al.20 However, in contrast to their report, we found no correlation between F0 and EVF. This disagreement may be due to a difference in dose-response relation between the levels of T and erythropoiesis, and between T and F0. Erythropoiesis is known to dose dependently respond to increased levels of androgens even in the supraphysiological range, whereas a number of other responses to androgens do not continue beyond a certain level within the normal reference range indicating a saturation of AR-mediated signaling. According to the results from the present study, it seems likely that the changes of the voice F0 values reach a maximum with physiological “male” T levels. This does-response mechanism is, to our knowledge, not known in the larynx and in the voice F0 values. The finding in Cosyns et al20 that a longer CAG repeat in the AR gene was found in the cases with lowest pitched voices is also in contrast to the concept that shorter CAG chains are associated with a stronger androgen response.12 No significant changes in Min and Max SPL and Leq during treatment were found, which is interesting, because vocally healthy

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Effects of Testosterone Treatment on Voice

males have been found to speak significantly louder than vocally healthy females.13,27 In the present study, the mean value of Max SPL from VRP was 96 dB (95% CI 94–97 dB) before treatment and 97 dB (95% CI 95–99 dB) after 24 months of treatment, which is lower than the reference value of 109 dB for vocally healthy Swedish males.25 The reason for these relatively low values of SPL during T treatment may depend on difficulties projecting the voice as described by Scheidt et al,17 as well as vocal instability or lack of confidence regarding the voice. One may speculate that there are physiological limitations in the vocal folds to produce higher SPL, because it is likely that the vocal fold length does not increase because of androgen treatment. This should be interesting to study in the future. If vocal fold length remains the same and the size of the vocal fold muscle increases, the glottal area and vocal fold amplitude during phonation will probably not increase, and thus not generate higher vocal fold closing rate, which is one way of increasing SPL.28 The VRP areas in the present study were smaller in comparison with reference data for vocally healthy Swedish and Australian males recorded with the same procedure.16,25 Smaller VRP frequency range before T treatment and during treatment may be due to some patients’ resistance to producing voice in high frequencies, and also lack of capacity to produce high pitches. A smaller VRP area could also depend on vocal instability during T treatment, which may lead to loss of certain frequencies and difficulties in registration of upper and lower SPL contours. Voice changes, that is, deepening of the voice pitch and vocal instability, have been described in a few studies investigating clinical side effects during T treatment.5,29 Vocal instability has also been described in previous studies on women with virilized voices due to medication with androgens or endogenous overproduction of androgens. The symptoms identified are lowering of the voice pitch, loss of high frequencies, vocal instability, hoarse voice quality, problems projecting the speaking voice, and dissatisfaction with the voice.30–36 In the present study, we excluded two participants who terminated T treatment. However, they performed voice assessments at 5 and 6 months after they stopped treatment with T and no changes were observed according to frequency values, which supports that virilization of the voice is permanent.34,35,37 More studies are needed regarding this topic. Androgen treatment In agreement with Wierckx and colleagues5 and Mueller et al,29 we also discovered a significant increase in T, with a predicted suppression of LH, and a significant increase in EVF (hematocrit) and decline in SHBG during treatment. A study by Nakamura and colleagues analyzed dose-response relationship of T treatment in terms of, for example, onset of deepening of the voice based on answers to questionnaires in 138 trans men.38 The authors found no dose-dependent effects on the percentage that had experienced this effect at 6 months after the start of treatment. The present study found that voice changes were not dose dependent at 12 months after the start of treatment. Self-ratings and need for voice therapy A majority of the trans men in the present study were satisfied with their voice after 12 months. However, 12 of 50 reported

9

symptoms such as vocal fatigue, vocal instability, strained voice quality, insufficient lowering of the pitch, difficulties projecting the voice, and problems with the voice sounding too young for their chronological age, and thus had received voice therapy. Therefore, it is important to identify such voice problems and symptoms during androgen treatment. Most trans men are probably not referred for voice assessment, possibly because the voice demonstrably lowers in pitch during T treatment. The participants who received voice therapy were given therapy between the start of treatment and the 24-month timepoint. The frequency range, as measured by the VRP, reflects the physiological frequency range and should not be affected by voice therapy. Minimum F0 is dependent on the size of the vocal folds that are affected by T. It would be interesting in the future to study the vocal folds’ anatomical changes during T treatment. The voice therapy may have slightly influenced the subjective ratings regarding vocal fatigue in the present study. We did not exclude those participants who rated symptoms of vocal fatigue because their data did not differ from the group in general, and the variation was large for the whole group. Future studies should evaluate effects of voice therapy in trans men and investigate eventual predictable factors for need of voice therapy for this patient group. One voice problem that was described was sounding too young, which is probably related to the vocal instability that may occur, making the patient sound like a pubertal boy. Wierckx and colleagues also reported that voice instability increased according to self-ratings in a 1-year prospective study of 53 trans men during T treatment.5 The reason why some trans men sound younger than their chronological age could also be due to the vocal tract length (VTL). The VTL affects the resonance (vocal formant) frequencies and how the voice is perceived. Women have a shorter VTL39,40 and higher formant frequencies, and a female voice is perceived as “brighter” than a male voice. A trans man with low F0 values and high vocal formant frequencies could be perceived as a younger male speaker in comparison with a male speaker with low formant frequencies. The need for voice therapy in trans men has been emphasized in earlier studies too.17,23 A sample survey including 16 subjects, who had been treated with T for at least 1 year, was conducted by Van Borsel et al.18 Of the 16, 14 subjects were pleased with their voices; however, two of 14 subjects would have liked a “heavier” voice, and one of 14 subjects was not satisfied because his voice was strained when he tried to speak in a lower pitch. Thus, 11 subjects were satisfied with their voice and did not need voice therapy or pitchlowering surgery, although eight of them had hoped for a faster and/or more pronounced voice change. Four subjects did receive voice therapy and were referred to pitch-lowering surgery. On the basis of those results, voice assessment during T treatment was recommended.18 Voice therapy programs need to be developed for trans men and the therapy needs to be evaluated. Our findings that higher self-ratings regarding satisfaction with the voice and being perceived as male on the phone correlated to lower F0 values is in congruence with findings presented by Scheidt et al.17 In that study, 14 trans men had been treated with T for between 2.5 months and 9.3 years, and voice characteristics and subjective voice function were examined. Most of the participants considered it important to be recognized as male from

ARTICLE IN PRESS 10 their voice and, 64% desired support to deal with their voice problems, that is, reduced vocal power, disturbed voice quality, problems with breathing, as well as body posture and tension. When vocal demands were taken into consideration, 79% of the participants were rated as being in need of voice therapy.17 It was concluded that voice therapy should be considered for trans men. The outcome of voice therapy has been reported in a followup study by Söderpalm et al23 including 22 trans women and three trans men. It was suggested that even if F0 is lowered because of androgen treatment in trans men, the decrease is not always enough, and that the need for voice therapy for this patient group could be underestimated.23 Another treatment option for some patients when the decrease in F0 is insufficient would be “pitch-lowering surgery”, for example, type 3 thyroplasty41; however, no outcome results have been reported so far for trans men. Further studies investigating how trans men are perceived by others through the use of listening tests are needed. How a voice is perceived by listeners is affected not only by the F0 but also by the voice quality, the resonance, and other aspects of speech and communication.22 Also, subjective ratings of the voice function of trans men seem important to investigate further, and so far, there is no validated voice-related quality of life questionnaire for trans men. Trans men are a heterogeneous group with different goals regarding the voice, voice linked to identity, and how they wish to be perceived by others.3,4,17 There is a need for a questionnaire about voice and identity,3,4 as well as questions that grasp the voice problems relevant for trans men, that is, vocal instability, vocal fatigue, and insufficient lowering of F0. Such a questionnaire should be developed and validated in the same way as the Transsexual Voice Questionnaire for trans women.42 The voice problems in trans men differ usually from those problems trans women describe, that is, too low pitch, dark voice quality, and loud voice, acoustically measured by low F0, low formant frequencies, and high SPL values.8,23 We strongly recommend a screening for trans men with the voice assessment as described in the present study complemented with a questionnaire to identify those who need voice therapy. A systematic assessment, including acoustic analyses and subjective data obtained from a questionnaire, can also be used for evaluation of voice therapy.

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In the present study, ratings concerning the statement I am worried that my voice will reveal my native sex varied considerably during treatment, that is, many of the participants were worried despite the fact that their voice F0 had reached a male range. There is also a need to define the content of voice therapy for trans men apart from treating the symptoms. We suggest that therapy should include ways of increasing the patients’ awareness of how the voice sounds and how it is perceived by others to support the patients’ confidence in speaking.3,4 Many patients who are referred to the Department of Speech and Language Pathology, Karolinska University Hospital for voice assessment stress the importance of getting an opportunity to systematically listen to their voice and voice changes during the process of T treatment. CONCLUSIONS Final F0 values for trans men were congruent with reference values from vocally healthy Swedish males after 12 months of androgen treatment, although the variation was considerable. Satisfaction with the voice varied especially before 12 months of androgen treatment, and lower F0 values correlated with greater satisfaction with the voice. It is important to detect the potential large subgroup of trans men who need voice therapy, due to problems associated with voice virilization such as vocal instability, vocal fatigue, and insufficient lowering of F0. We strongly recommend following the voice change in trans men during at least the first year of hormone treatment with systematic voice recordings and voice assessments. Acknowledgments The authors want to thank Elisabeth Berg for statistics support, Elisabet Borg for valuable discussions about rating scales, Cecilia Dhejne, Marie Degerblad, and Eva B Holmberg for valuable comments on the manuscript, and Janet Holmén for linguistic revision of a draft of this paper. This study was supported by grants from the Swedish Research Council, the Aina Börjeson Foundation for Speech Language Pathology Research and Treatment, Foundation Frimurare Barnhuset, the Stockholm City Council, and funding provided by the Centre for Andrology and Sexual Medicine (CASM).

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Effects of Testosterone Treatment on Voice

APPENDIX Voice assessments made for each participant before treatment, and after 3, 6, 12, 18, and 24 months (time range) based on what timepoint the participant came (shaded with gray)

Participants 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

Before Treatment

3 Months (2–5)

6 Months (5–10)

12 Months (11–15)

18 Months (16–21)

24 Months (22–36)

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