- Email: [email protected]
Evaluation of musical skills in children with a diagnosis of an auditory processing disorder
International Journal of Pediatric Otorhinolaryngology 74 (2010) 633–636
Contents lists available at ScienceDirect
International Journal of Pediatric Otorhinolaryngology journal homepage: www.elsevier.com/locate/ijporl
Evaluation of musical skills in children with a diagnosis of an auditory processing disorder Deborah Olakunbi a, Doris-Eva Bamiou b,*, Lauren Stewart c, Linda M. Luxon b a
Medical School, University College London, Gower Street, London WC1E 6BT, United Kingdom Ear Institute (University College London), 332 Gray’s Inn Rd London, WC1X 8EE, United Kingdom c Department of Psychology, Room 202/3 Whitehead Building, Goldsmiths, University of London New Cross, London, SE14 6NW, United Kingdom b
A R T I C L E I N F O
A B S T R A C T
Article history: Received 12 January 2010 Accepted 2 March 2010 Available online 31 March 2010
Impaired musical skills are reported in parental questionnaires to be present in children with an auditory processing disorder (APD). Objectives: To formally assess musical skills in children with a diagnosis of APD. Methods: We used a validated musical test battery with extensive normative pediatric data, the Gordon’s Musical Aptitude Profile and the tests of metre and melody in particular, in order to assess the musical skills of 8 children with a previously given diagnosis of APD (APD group) and 8 normal controls (control group) aged 7–15 years old. The two groups were well matched for age, sex, handedness, socioeconomic factors and musical training. Results: The APD group had significantly lower metre percentile scores than normal children (mean difference 28.9, p = 0.003). Melody scores tended to be lower in the APD group than in the controls, but this did not reach significance, possibly due to low power of the study. Conclusion: This is the first study that systematically assesses musical skills in children with a formal diagnosis of APD in the absence of other developmental disorders. The APD group did significantly worse than the control group in judging metre. Musical skills assessment in children with APD may help constrain our understanding of this heterogeneous condition and possibly inform the management plan for these children. ß 2010 Elsevier Ireland Ltd. All rights reserved.
Keywords: Auditory processing disorder Musical skills Metre Melody
1. Introduction Auditory processing disorders (APD) exist as a collection of disorders in which there are deficits in the perceptual processing of auditory signals within the central auditory pathway [1,2]. Individuals with APD may have a range of deficits, including deficits in sound localization, auditory discrimination, auditory pattern recognition, temporal processing, auditory performance in competing acoustic signals (including dichotic listening); and auditory performance with degraded acoustic signals [1] as well as with sound separation and grouping [2]. In children, these deficits may manifest with primary symptoms such as uncertainty in what is heard, particularly in background noise, difficulties in understanding spoken instructions or understanding rapid or degraded speech and following spoken instructions [3], and they may also have a reduced ability for and appreciation of music [1]. Music has three fundamental component parts: pitch (broadly defined as the perceptual correlate of the fundamental frequency),
* Corresponding author. Tel.: +44 7813716768. E-mail address: [email protected] (D.-E. Bamiou). 0165-5876/$ – see front matter ß 2010 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ijporl.2010.03.008
timbre (the percept that allows to distinguish which instrument produces the music) and temporal structure (rhythm and metre). These elements are processed by different neural substrates of the brain [4]. It has been proposed that musical processing is modular, i.e. underpinned by an information processing system which is specific to the processing of music, and this theory is supported by the findings of dissociated impairments in music versus speech recognition abilities in some brain damaged subjects post brain damage [5]. The term ‘‘congenital amusia’’ refers to a developmental disorder characterised by abnormal perception of music in the presence of otherwise normal hearing and cognition [6]. This condition may be determined on a single gene basis, although a polygenic basis is still possible [7]. Children with suspected APD are anecdotally reported to have reduced musical skills. However, systematic studies of musical perception in this population are scarce. Meister et al. [8] conducted a questionnaire study to identify listening differences between an APD group and a normal control group. A musical component featured in their survey with the questions ‘‘Does your child clap to the wrong rhythm when listening to music?’’ and ‘‘Does your child sing or hum a wrong melody when repeating a piece of music?’’. The responses showed a significant difference (at the 1% level) between the two groups. These findings indicate that
634
D. Olakunbi et al. / International Journal of Pediatric Otorhinolaryngology 74 (2010) 633–636
assessing musical perceptual skills may help to constrain our understanding of the nature and possible heterogeneity of APD. The present study seeks to study musical perception by means of the Gordon’s Musical Aptitude Profile and a questionnaire of musical behaviour in children with diagnosed APD. Gordon’s Musical Aptitude Profile (GMAP) [9] is a validated test of musical aptitude and can provide an extensive assessment of musical potential in children and adults [10]. It is the ‘‘most commonly used test of musical ability in the USA and has the most extensive normative data on more than 12,000 children’’ [10]. 2. Participants and methods 2.1. Subjects This case–control study included of a group of children with a diagnosis of APD, and a control group of age matched normal children. The study was approved by the Research Ethics Committee of the Great Ormond Street Hospital/Institute of Child Health (reference number: 06/Q0508/134) and informed consent was obtained by study participants and their parents. APD participants were recruited from consecutive cases seen from September 2006 to May 2007 at the Auditory Processing Clinic at Great Ormond Street Hospital. The inclusion and exclusion criteria for the APD group consisted of the following. 2.1.1. Inclusion criteria All case subjects were age 7 and above, had been referred to the Department for an auditory processing assessment because of ‘‘listening’’ difficulties, and had been given a clinical diagnosis of an APD. Both at the time of the APD diagnosis and in the day of the study, they had normal hearing thresholds (better than 20 dBHL in each frequency of 500, 1000, 2000, 4000 and 8000 Hz) and normal tympanometry in both ears. Diagnosis of APD had been previously made after standard clinical test protocol (see [11,12] for test details) and other assessments and based upon the findings of abnormalities in at least two behavioural central auditory tests, one of which should be non-speech [12]; exclusion of other potential confounders by means of age appropriate, validated Speech & Language and Educational Psychology assessments conducted by licensed professionals. (These assessments are part of the standard clinical test protocol at the Great Ormond Street Clinic and will not be described in this paper).
2.1.2. Exclusion criteria The presence of a low IQ (one statistical deviation below average), a diagnosis of autism, attention deficit hyperactivity disorder, neurological disorders or a diagnosis of auditory neuropathy (based on findings of absent or abnormal ABR and/ or absent or abnormal acoustic reflexes and normal otoacoustic emissions). The control group was recruited from families of all grades of hospital staff. We endeavoured to keep the control group as closely match to the APD group as possible for sex, age, handedness (defined on the basis of the hand used to write) and socioeconomic background ranked according to an ‘‘index of multiple deprivation’’ as calculated on the basis of a combination of indices including employment, education, housing, health and crime and calculated on the basis of the study participant’s post code (see http://www.neighbourhood.statistics.gov.uk/dissemination/). Inclusion and exclusion criteria for the controls were as follows.
2.1.3. Inclusion criteria All subjects were age 7 and above and at a mainstream school. They had normal hearing thresholds (as defined above) in both ears. 2.1.4. Exclusion criteria Neurological problems, known developmental disorders or low IQ (less than 1 SD below average). 2.2. Test protocol The test protocol consisted of: - Baseline Audiometry, including tympanometry (to assess middle ear function) and pure tone audiometry (PTA) (to assess hearing thresholds) as per standard clinical procedures [13]. - Auditory Processing Tests were all available on a compact disc (CD) (Audiology Illustrated) which was played with a Sony CD player and routed through the speech circuitry of the GSI 61 audiometer and TDH-49 headphones at a 50 dB sensation level (as per test instructions). Outcome measures were percentage correct responses for each ear, that were classified as normal or abnormal according to departmental norms. Tests included dichotic digits [14]: a different pair of numbers between 1 and 10 is presented simultaneously to each ear (20 pairs in total for each ear) and the child has to repeat all 4 numbers frequency pattern [15]: a sequence of three tone bursts, a combination of a low- and high-frequency tone is presented to each ear, and the child has to label the sequence (20 sequences were presented to each ear). duration pattern [16]: a sequence of three tone bursts, a combination of a long- and short-duration tone is presented to each ear, and the child has to label the sequence (20 sequences were presented to each ear). - The Musical Aptitude Test (GMAP [9]) was presented binaurally via a CD recording played via the Windows Media player of Dell Optiplex GX280 Intel Pentium1 desktop computer and presented through HD-600 headphones (Sennheiser) at a comfortable sound level for the subject. We administered the reduced form of GMAP (as per the test manual’s instructions), consisting of two subtests—Melody and Metre, in order to enable us to complete all the tests in one session. For both subtests, after training, 40 pairs of short musical pieces of western type music were presented to each child. The child was instructed to judge and report orally whether the two phrases within each pair sounded similar or different. Both subtests provided raw, standard and percentile correct scores per 12 month age group. - A concise non-validated Musical Questionnaire designed to determine level of musical training background, including questions concerning musical achievements and amount of daily practise was used to determine other aspects of musical behaviour not obtained through the previous tests. This was completed by the study participant and their parent, together, before the tests were administered. 2.3. Statistical analysis Statistical analysis was conducted with the statistical package for social sciences—SPSS. The percentile test scores for the GMAP and the test scores for the auditory processing tests of the two groups were compared with the use of the Mann–Whitney statistical test. The 95% Confidence Intervals (derived from the Independent samples t-test) were also obtained. Spearman’s Rank correlation coefficient and tests of multiple hierarchical regression were used to analyse any relationship between the GMAP subtests and the auditory processing tests. The Mann–Whitney statistical
D. Olakunbi et al. / International Journal of Pediatric Otorhinolaryngology 74 (2010) 633–636 Table 1 Population data.
n Sex n (%) Male Female Age Mean (SD)
Case
Control
p
8
8
–
5 (62.5) 3 (47.5)
4 (50) 4 (50)
In both measures of GMAP subtests, the APD group had lower percentile scores compared with the control group, however this was only significant for the Metre subtest (p = 0.003) (Table 2). The APD group scored significantly lower than controls for tests of frequency pattern and duration pattern but not the dichotic digit test (Table 3). There was a significant correlation between both frequency and duration pattern test right and left ear scores and melody percentile, and duration pattern test right and left ear scores and metre percentile at p < 0.05 (Table 4). There was no significant difference in melody or metre percentiles in children with, versus without, formal musical training (Table 5).
0.626
11.5 (1.67)
10.3 (3.09)
Handedness n (%) Right Left
8 (100) 0
8 (100) 0
Deprivation index Mean (SD)
191 (125)
151 (125)
0.460
Musical family mean (SD) Yes 7 (87.5) No 1 (12.5)
8 (100) 0 (0)
0.317
Musical training mean (SD) Yes 6 (75) No 2 (25)
6 (75) 2 (25)
1.00
635
0.301
1
4. Discussion To our knowledge, this is the first study that systematically assesses musical skills by means of a validated musical test battery in a group of children with a formal diagnosis of APD in the absence of other developmental disorders. Results show that the APD group did worse than the control group in both measures of musical aptitude, but this was only significant for the metre subtest. This indicates that our APD group has reduced musical skills in comparison to the control group, consistent with parental reports as per the Meister et al. study [8]. Interestingly, a significant deficit in metre processing with apparent normal melody processing is the inverse pattern of deficits seen in the developmental disorder of congenital amusia, where individuals have difficulty in perceiving music and recognizing familiar tunes [10]. In many cases of congenital amusia, temporal processing appears to be spared, though Foxton et al. [17] have shown that processing of temporal cues may be compromised in the context of a changing melodic stimulus. There are various implications to the present study’s findings. Firstly, children with APD may be experiencing difficulties on
test and the Independent Samples t-test were also used to identify any differences between those participants with formal musical training and those without in all study groups. A chi-square test was used to assess difference in proportions between the two groups. A p value of 0.05 was accepted as statistically significant. 3. Results We recruited 8 children with a diagnosis of APD and 8 controls (age range 7.3–14.8 years). There were no significant differences between the two study groups in terms of sex, age, handedness, index of multiple deprivation, having a musical family or undertaking musical training (p > 0.05) (Table 1). Table 2 GMAP scores.
Melody percentile Metre percentile *
APD mean (SD)
Control mean (SD)
Mean difference (95% CI)
Mann–Whitney p-value
56.6 (31.5) 58.0 (16.1)
82.1 (19.3) 86.9 (11.2)
25.5 ( 2.50, 53.5) 28.9 (14.0, 43.7)
0.114 0.003*
Significance better than the 5% level in a 2 tailed Mann–Whitney statistical test.
Table 3 Mean auditory processing test results scores for the APD and control groups.
DDR DDL FPTR FPTL DPTR DPTL
APD mean (SD)
Control mean (SD)
Mean difference (95% CI)
Mann–Whitney p-value
87.9 84.1 54.2 51.0 49.4 49.3
95.0 91.1 86.3 93.8 80.0 88.6
7.08 ( 2.25, 16.4) 6.90 ( 1.38, 15.2) 32.1 (1.49, 62.7) 42.7 (0.85, 84.6) 30.6 (8.94, 52.2) 39.3 (8.08, 70.5)
0.068 0.090 0.038* 0.026* 0.019* 0.063
(9.41) (7.36) (29.1) (40.0) (21.0) (37.0)
(6.68) (6.80) (13.6) (10.6) (14.6) (13.8)
APD: auditory processing disorder DDR/L: dichotic digits right/left; FPTR/L: frequency pattern test right/left; DPTR/L: duration pattern test right/left. * Significance better than the 5% level in a 2 tailed Mann–Whitney statistical test.
Table 4 Correlation of GMAP scores with auditory processing test scores. FPTR *
FPTL
DPTR
DPTL
Melody percentile
Spearman’s Coefficient (2-tailed Sig.)
0.611 (0.020)
0.854** (0.000)
0.746** (0.003)
0.645* (0.017)
Metre percentile
Spearman’s Coefficient (2-tailed Sig.)
0.408 (0.147)
0.456 (0.101)
0.729** (0.005)
0.630* (0.021)
FPTR/L: frequency pattern test right/left; DPTR/L: duration pattern test right/left. * Significance better than the 5% level in a 2 tailed Mann–Whitney statistical test.
D. Olakunbi et al. / International Journal of Pediatric Otorhinolaryngology 74 (2010) 633–636
636 Table 5 Mean GMAP scores for all participants.
Melody percentile Metre percentile
No formal musical training mean (SD)
Formal musical training mean (SD)
73 (15.0) 65.5 (25.0)
68.2 (32.2) 74.7 (18.8)
Mean difference (95% CI) 4.83 ( 21.2, 30.9) 9.25 ( 34.4, 15.9)
Mann–Whitney p-value 0.761 0.463
This group has been separated into those who have received formal musical training and those who have not.
participation in musical activities compared to their peer group. In addition, this reduced musical ability may also affect language and literacy skills, as indicated by various studies. Melody percentiles were not significantly different in the APD vs. the control group, however performance of the APD group (note the SD in Table 2) for this test was more variable than in the controls, and confidence intervals (Table 2) indicated that lack of significance might be due to low statistical power. Conversely, frequency (pitch) pattern scores were significantly lower in the APD vs. the control group. Pitch pattern perception correlates with both phonological skill and reading ability [18]. Norton et al. [19] have also showed in a young population, a significant positive correlation between musical aptitude and phonemic awareness (i.e. the separation of words into phonemes), a skill essential in reading and spelling tasks. Another such study by Anvari et al. [20] found that musical ability and perception had an effect on reading ability in children even after the impact of phonemic awareness is controlled for. The relationship between musical and phonemic ability is also supported by studies on reading difficulties and musical timing skills. One such study by Overy et al. [21] carried out musical aptitude tests on children with dyslexia. Results showed that, compared to control children, those with dyslexia had reduced skills in timing, rhythm, and timbre discrimination. Different forms of auditory training, chosen on the basis of the identified deficits, have been applied to children with APD with some reported benefit in different studies [22]. Musical lessons targeted to the particular areas of deficit might be an effective and fun means of improving some of the auditory processing difficulties for this population. Finally, assessing musical skills in children with APD may help differentiate symptom profiles of this complex clinical presentation. Subjects with congenital amusia have reduced white matter in the region of the right inferior frontal gyrus on MRI [23], while Peretz et al. [24] comment on a hereditary component of amusia and hence a responsible gene. Initial results in our group of APD children showed an inverse pattern of musical deficits than that seen in the developmental disorder of congenital amusia. It may be possible that differences in brain structure, whether local or otherwise are also present in those with APD, and candidate brain regions may well be identified on the presence of specific deficits. 5. Conclusion Children with APD have been reported to have a reduced ability in and appreciation for music. The results of the present study have shown that a group of children with APD performed worse in musical aptitude tests than controls. In addition, this group displayed lower auditory processing skills in tests shown to correlate with musical aptitude measures. Assessing in detail musical skills in children with APD may further understanding of this heterogeneous condition and possibly help to determine genotype, and further research is needed.
Conflict of interest statement None. References [1] American Speech-Language Hearing Association, Evidence-based practice in communication disorders: An introduction [Technical report], 2004, http:// www.asha.org/NR/rdonlyres/B36BF8F8-C4C3-4E86-8FAD-26D76F130CBF/0/ ebpTR.pdf (retrieved 09.12.08). [2] Auditory Processing Disorder (APD) Steering Committee, British Society of Audiology. Interim position statement on APD. 2007. Retrieved December 2009 from: http://www.thebsa.org.uk/apd/Home.htm#working def. [3] J. Jerger, F. Musiek, Report of the consensus conference on the diagnosis of auditory processing disorders in school-aged children, J. Am. Acad. Audiol. 11 (2000) 467–474. [4] L. Stewart, K. von Kriegstein, J.D. Warren, T.D. Griffiths, Music and the brain: disorders of musical listening, Brain 129 (Pt 10) (2006) 2533–2553. [5] I. Peretz, M. Coltheart, Modularity of music processing, Nat. Neurosci. 6 (7) (2003) 688–691. [6] J. Ayotte, I. Peretz, K. Hyde, Congenital amusia: a group study of adults afflicted with a music-specific disorder, Brain 125 (Pt 2) (2002) 238–251. [7] T.D. Griffiths, Tone deafness: a model complex cortical phenotype, Clin. Med. 8 (6) (2008) 592–595. [8] H. Meister, H. von Wedel, M. Walger, Psychometric evaluation of children with suspected auditory processing disorders (APDs) using a parent-answered survey, Int. J. Audiol. 43 (8) (2004) 431–437. [9] E. Gordon, Musical Aptitude Profile, GIA, Chicago, 2001. [10] I. Peretz, A.S. Champod, K. Hyde, Varieties of musical disorders. The Montreal Battery of Evaluation of Amusia, Ann. N.Y. Acad. Sci. 999 (2003) 58–75. [11] D.E. Bamiou, S. Free, S. Sisodiya, F.E. Musiek, W.K. Chong, D. Gadian, K. Williamson, V. van Heyningen, A. Moore, L.M. Luxon, Auditory processing deficits and MRIdocumented brain abnormalities in children with PAX6 mutations, Arch. Pediatr. Adolesc. Med. 161 (2007) 463–469. [12] P. Dawes, D.V. Bishop, T. Sirimanna, D.E. Bamiou, Profile and aetiology of children diagnosed with auditory processing disorder (APD), Int. J. Pediatr. Otorhinolaryngol. 72 (4) (2008) 483–489. [13] British Society of Audiology, Recommended procedure for pure tone audiometry using a manually operated instrument, Br. J. Audiol. 15 (1981) 213–216. [14] F.E. Musiek, Assessment of central auditory dysfunction: the Dichotic Digit Test revisited, Ear Hear. 4 (1983) 79–83. [15] F.E. Musiek, Frequency (pitch) and duration pattern tests, J. Am. Acad. Audiol. 5 (1994) 265–268. [16] F.E. Musiek, J.A. Baran, M.L. Pinheiro, Duration pattern recognition in normal subjects and patients with cerebral and cochlear lesions, Audiology 29 (1990) 304–313. [17] J.M. Foxton, R.K. Nandy, T.D. Griffiths, Rhythm deficits in ‘tone deafness’, Brain Cogn. 62 (1) (2006) 24–29. [18] J.M. Foxton, J.B. Talcott, C. Witton, H. Brace, F. McIntyre, T.D. Griffiths, Reading skills are related to global, but not local, acoustic pattern perception, Nat. Neurosci. 6 (4) (2003) 343–344. [19] A. Norton, E. Winner, K. Cronin, K. Overy, D.J. Lee, G. Schlaug, Are there preexisting neural, cognitive, or motoric markers for musical ability? Brain Cogn. 59 (2) (2005) 124–134. [20] S.H. Anvari, L.J. Trainor, J. Woodside, B.A. Levy, Relations among musical skills, phonological processing, and early reading ability in preschool children, J. Exp. Child Psychol. 83 (2) (2002) 111–130. [21] K. Overy, A. Norton, K. Cronin, E. Winner, G. Schlaug, Examining rhythm and melody processing in young children using FMRI, Ann. N.Y. Acad. Sci. 1060 (2005) 210–218. [22] D.E. Bamiou, N. Campbell, T.S. Sirimanna, Management of auditory processing disorders, Audiol. Med. 4 (2006) 46–56. [23] K.L. Hyde, R.J. Zatorre, T.D. Griffiths, J.P. Lerch, I. Peretz, Morphometry of the amusic brain: a two-site study, Brain 129 (Pt 10) (2006) 2562–2570. [24] I. Peretz, S. Cummings, M.P. Dube´, The genetics of congenital amusia (tone deafness): a family-aggregation study, Am. J. Hum. Genet. 81 (3) (2007) 582–588.
Contents lists available at ScienceDirect
International Journal of Pediatric Otorhinolaryngology journal homepage: www.elsevier.com/locate/ijporl
Evaluation of musical skills in children with a diagnosis of an auditory processing disorder Deborah Olakunbi a, Doris-Eva Bamiou b,*, Lauren Stewart c, Linda M. Luxon b a
Medical School, University College London, Gower Street, London WC1E 6BT, United Kingdom Ear Institute (University College London), 332 Gray’s Inn Rd London, WC1X 8EE, United Kingdom c Department of Psychology, Room 202/3 Whitehead Building, Goldsmiths, University of London New Cross, London, SE14 6NW, United Kingdom b
A R T I C L E I N F O
A B S T R A C T
Article history: Received 12 January 2010 Accepted 2 March 2010 Available online 31 March 2010
Impaired musical skills are reported in parental questionnaires to be present in children with an auditory processing disorder (APD). Objectives: To formally assess musical skills in children with a diagnosis of APD. Methods: We used a validated musical test battery with extensive normative pediatric data, the Gordon’s Musical Aptitude Profile and the tests of metre and melody in particular, in order to assess the musical skills of 8 children with a previously given diagnosis of APD (APD group) and 8 normal controls (control group) aged 7–15 years old. The two groups were well matched for age, sex, handedness, socioeconomic factors and musical training. Results: The APD group had significantly lower metre percentile scores than normal children (mean difference 28.9, p = 0.003). Melody scores tended to be lower in the APD group than in the controls, but this did not reach significance, possibly due to low power of the study. Conclusion: This is the first study that systematically assesses musical skills in children with a formal diagnosis of APD in the absence of other developmental disorders. The APD group did significantly worse than the control group in judging metre. Musical skills assessment in children with APD may help constrain our understanding of this heterogeneous condition and possibly inform the management plan for these children. ß 2010 Elsevier Ireland Ltd. All rights reserved.
Keywords: Auditory processing disorder Musical skills Metre Melody
1. Introduction Auditory processing disorders (APD) exist as a collection of disorders in which there are deficits in the perceptual processing of auditory signals within the central auditory pathway [1,2]. Individuals with APD may have a range of deficits, including deficits in sound localization, auditory discrimination, auditory pattern recognition, temporal processing, auditory performance in competing acoustic signals (including dichotic listening); and auditory performance with degraded acoustic signals [1] as well as with sound separation and grouping [2]. In children, these deficits may manifest with primary symptoms such as uncertainty in what is heard, particularly in background noise, difficulties in understanding spoken instructions or understanding rapid or degraded speech and following spoken instructions [3], and they may also have a reduced ability for and appreciation of music [1]. Music has three fundamental component parts: pitch (broadly defined as the perceptual correlate of the fundamental frequency),
* Corresponding author. Tel.: +44 7813716768. E-mail address: [email protected] (D.-E. Bamiou). 0165-5876/$ – see front matter ß 2010 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ijporl.2010.03.008
timbre (the percept that allows to distinguish which instrument produces the music) and temporal structure (rhythm and metre). These elements are processed by different neural substrates of the brain [4]. It has been proposed that musical processing is modular, i.e. underpinned by an information processing system which is specific to the processing of music, and this theory is supported by the findings of dissociated impairments in music versus speech recognition abilities in some brain damaged subjects post brain damage [5]. The term ‘‘congenital amusia’’ refers to a developmental disorder characterised by abnormal perception of music in the presence of otherwise normal hearing and cognition [6]. This condition may be determined on a single gene basis, although a polygenic basis is still possible [7]. Children with suspected APD are anecdotally reported to have reduced musical skills. However, systematic studies of musical perception in this population are scarce. Meister et al. [8] conducted a questionnaire study to identify listening differences between an APD group and a normal control group. A musical component featured in their survey with the questions ‘‘Does your child clap to the wrong rhythm when listening to music?’’ and ‘‘Does your child sing or hum a wrong melody when repeating a piece of music?’’. The responses showed a significant difference (at the 1% level) between the two groups. These findings indicate that
634
D. Olakunbi et al. / International Journal of Pediatric Otorhinolaryngology 74 (2010) 633–636
assessing musical perceptual skills may help to constrain our understanding of the nature and possible heterogeneity of APD. The present study seeks to study musical perception by means of the Gordon’s Musical Aptitude Profile and a questionnaire of musical behaviour in children with diagnosed APD. Gordon’s Musical Aptitude Profile (GMAP) [9] is a validated test of musical aptitude and can provide an extensive assessment of musical potential in children and adults [10]. It is the ‘‘most commonly used test of musical ability in the USA and has the most extensive normative data on more than 12,000 children’’ [10]. 2. Participants and methods 2.1. Subjects This case–control study included of a group of children with a diagnosis of APD, and a control group of age matched normal children. The study was approved by the Research Ethics Committee of the Great Ormond Street Hospital/Institute of Child Health (reference number: 06/Q0508/134) and informed consent was obtained by study participants and their parents. APD participants were recruited from consecutive cases seen from September 2006 to May 2007 at the Auditory Processing Clinic at Great Ormond Street Hospital. The inclusion and exclusion criteria for the APD group consisted of the following. 2.1.1. Inclusion criteria All case subjects were age 7 and above, had been referred to the Department for an auditory processing assessment because of ‘‘listening’’ difficulties, and had been given a clinical diagnosis of an APD. Both at the time of the APD diagnosis and in the day of the study, they had normal hearing thresholds (better than 20 dBHL in each frequency of 500, 1000, 2000, 4000 and 8000 Hz) and normal tympanometry in both ears. Diagnosis of APD had been previously made after standard clinical test protocol (see [11,12] for test details) and other assessments and based upon the findings of abnormalities in at least two behavioural central auditory tests, one of which should be non-speech [12]; exclusion of other potential confounders by means of age appropriate, validated Speech & Language and Educational Psychology assessments conducted by licensed professionals. (These assessments are part of the standard clinical test protocol at the Great Ormond Street Clinic and will not be described in this paper).
2.1.2. Exclusion criteria The presence of a low IQ (one statistical deviation below average), a diagnosis of autism, attention deficit hyperactivity disorder, neurological disorders or a diagnosis of auditory neuropathy (based on findings of absent or abnormal ABR and/ or absent or abnormal acoustic reflexes and normal otoacoustic emissions). The control group was recruited from families of all grades of hospital staff. We endeavoured to keep the control group as closely match to the APD group as possible for sex, age, handedness (defined on the basis of the hand used to write) and socioeconomic background ranked according to an ‘‘index of multiple deprivation’’ as calculated on the basis of a combination of indices including employment, education, housing, health and crime and calculated on the basis of the study participant’s post code (see http://www.neighbourhood.statistics.gov.uk/dissemination/). Inclusion and exclusion criteria for the controls were as follows.
2.1.3. Inclusion criteria All subjects were age 7 and above and at a mainstream school. They had normal hearing thresholds (as defined above) in both ears. 2.1.4. Exclusion criteria Neurological problems, known developmental disorders or low IQ (less than 1 SD below average). 2.2. Test protocol The test protocol consisted of: - Baseline Audiometry, including tympanometry (to assess middle ear function) and pure tone audiometry (PTA) (to assess hearing thresholds) as per standard clinical procedures [13]. - Auditory Processing Tests were all available on a compact disc (CD) (Audiology Illustrated) which was played with a Sony CD player and routed through the speech circuitry of the GSI 61 audiometer and TDH-49 headphones at a 50 dB sensation level (as per test instructions). Outcome measures were percentage correct responses for each ear, that were classified as normal or abnormal according to departmental norms. Tests included dichotic digits [14]: a different pair of numbers between 1 and 10 is presented simultaneously to each ear (20 pairs in total for each ear) and the child has to repeat all 4 numbers frequency pattern [15]: a sequence of three tone bursts, a combination of a low- and high-frequency tone is presented to each ear, and the child has to label the sequence (20 sequences were presented to each ear). duration pattern [16]: a sequence of three tone bursts, a combination of a long- and short-duration tone is presented to each ear, and the child has to label the sequence (20 sequences were presented to each ear). - The Musical Aptitude Test (GMAP [9]) was presented binaurally via a CD recording played via the Windows Media player of Dell Optiplex GX280 Intel Pentium1 desktop computer and presented through HD-600 headphones (Sennheiser) at a comfortable sound level for the subject. We administered the reduced form of GMAP (as per the test manual’s instructions), consisting of two subtests—Melody and Metre, in order to enable us to complete all the tests in one session. For both subtests, after training, 40 pairs of short musical pieces of western type music were presented to each child. The child was instructed to judge and report orally whether the two phrases within each pair sounded similar or different. Both subtests provided raw, standard and percentile correct scores per 12 month age group. - A concise non-validated Musical Questionnaire designed to determine level of musical training background, including questions concerning musical achievements and amount of daily practise was used to determine other aspects of musical behaviour not obtained through the previous tests. This was completed by the study participant and their parent, together, before the tests were administered. 2.3. Statistical analysis Statistical analysis was conducted with the statistical package for social sciences—SPSS. The percentile test scores for the GMAP and the test scores for the auditory processing tests of the two groups were compared with the use of the Mann–Whitney statistical test. The 95% Confidence Intervals (derived from the Independent samples t-test) were also obtained. Spearman’s Rank correlation coefficient and tests of multiple hierarchical regression were used to analyse any relationship between the GMAP subtests and the auditory processing tests. The Mann–Whitney statistical
D. Olakunbi et al. / International Journal of Pediatric Otorhinolaryngology 74 (2010) 633–636 Table 1 Population data.
n Sex n (%) Male Female Age Mean (SD)
Case
Control
p
8
8
–
5 (62.5) 3 (47.5)
4 (50) 4 (50)
In both measures of GMAP subtests, the APD group had lower percentile scores compared with the control group, however this was only significant for the Metre subtest (p = 0.003) (Table 2). The APD group scored significantly lower than controls for tests of frequency pattern and duration pattern but not the dichotic digit test (Table 3). There was a significant correlation between both frequency and duration pattern test right and left ear scores and melody percentile, and duration pattern test right and left ear scores and metre percentile at p < 0.05 (Table 4). There was no significant difference in melody or metre percentiles in children with, versus without, formal musical training (Table 5).
0.626
11.5 (1.67)
10.3 (3.09)
Handedness n (%) Right Left
8 (100) 0
8 (100) 0
Deprivation index Mean (SD)
191 (125)
151 (125)
0.460
Musical family mean (SD) Yes 7 (87.5) No 1 (12.5)
8 (100) 0 (0)
0.317
Musical training mean (SD) Yes 6 (75) No 2 (25)
6 (75) 2 (25)
1.00
635
0.301
1
4. Discussion To our knowledge, this is the first study that systematically assesses musical skills by means of a validated musical test battery in a group of children with a formal diagnosis of APD in the absence of other developmental disorders. Results show that the APD group did worse than the control group in both measures of musical aptitude, but this was only significant for the metre subtest. This indicates that our APD group has reduced musical skills in comparison to the control group, consistent with parental reports as per the Meister et al. study [8]. Interestingly, a significant deficit in metre processing with apparent normal melody processing is the inverse pattern of deficits seen in the developmental disorder of congenital amusia, where individuals have difficulty in perceiving music and recognizing familiar tunes [10]. In many cases of congenital amusia, temporal processing appears to be spared, though Foxton et al. [17] have shown that processing of temporal cues may be compromised in the context of a changing melodic stimulus. There are various implications to the present study’s findings. Firstly, children with APD may be experiencing difficulties on
test and the Independent Samples t-test were also used to identify any differences between those participants with formal musical training and those without in all study groups. A chi-square test was used to assess difference in proportions between the two groups. A p value of 0.05 was accepted as statistically significant. 3. Results We recruited 8 children with a diagnosis of APD and 8 controls (age range 7.3–14.8 years). There were no significant differences between the two study groups in terms of sex, age, handedness, index of multiple deprivation, having a musical family or undertaking musical training (p > 0.05) (Table 1). Table 2 GMAP scores.
Melody percentile Metre percentile *
APD mean (SD)
Control mean (SD)
Mean difference (95% CI)
Mann–Whitney p-value
56.6 (31.5) 58.0 (16.1)
82.1 (19.3) 86.9 (11.2)
25.5 ( 2.50, 53.5) 28.9 (14.0, 43.7)
0.114 0.003*
Significance better than the 5% level in a 2 tailed Mann–Whitney statistical test.
Table 3 Mean auditory processing test results scores for the APD and control groups.
DDR DDL FPTR FPTL DPTR DPTL
APD mean (SD)
Control mean (SD)
Mean difference (95% CI)
Mann–Whitney p-value
87.9 84.1 54.2 51.0 49.4 49.3
95.0 91.1 86.3 93.8 80.0 88.6
7.08 ( 2.25, 16.4) 6.90 ( 1.38, 15.2) 32.1 (1.49, 62.7) 42.7 (0.85, 84.6) 30.6 (8.94, 52.2) 39.3 (8.08, 70.5)
0.068 0.090 0.038* 0.026* 0.019* 0.063
(9.41) (7.36) (29.1) (40.0) (21.0) (37.0)
(6.68) (6.80) (13.6) (10.6) (14.6) (13.8)
APD: auditory processing disorder DDR/L: dichotic digits right/left; FPTR/L: frequency pattern test right/left; DPTR/L: duration pattern test right/left. * Significance better than the 5% level in a 2 tailed Mann–Whitney statistical test.
Table 4 Correlation of GMAP scores with auditory processing test scores. FPTR *
FPTL
DPTR
DPTL
Melody percentile
Spearman’s Coefficient (2-tailed Sig.)
0.611 (0.020)
0.854** (0.000)
0.746** (0.003)
0.645* (0.017)
Metre percentile
Spearman’s Coefficient (2-tailed Sig.)
0.408 (0.147)
0.456 (0.101)
0.729** (0.005)
0.630* (0.021)
FPTR/L: frequency pattern test right/left; DPTR/L: duration pattern test right/left. * Significance better than the 5% level in a 2 tailed Mann–Whitney statistical test.
D. Olakunbi et al. / International Journal of Pediatric Otorhinolaryngology 74 (2010) 633–636
636 Table 5 Mean GMAP scores for all participants.
Melody percentile Metre percentile
No formal musical training mean (SD)
Formal musical training mean (SD)
73 (15.0) 65.5 (25.0)
68.2 (32.2) 74.7 (18.8)
Mean difference (95% CI) 4.83 ( 21.2, 30.9) 9.25 ( 34.4, 15.9)
Mann–Whitney p-value 0.761 0.463
This group has been separated into those who have received formal musical training and those who have not.
participation in musical activities compared to their peer group. In addition, this reduced musical ability may also affect language and literacy skills, as indicated by various studies. Melody percentiles were not significantly different in the APD vs. the control group, however performance of the APD group (note the SD in Table 2) for this test was more variable than in the controls, and confidence intervals (Table 2) indicated that lack of significance might be due to low statistical power. Conversely, frequency (pitch) pattern scores were significantly lower in the APD vs. the control group. Pitch pattern perception correlates with both phonological skill and reading ability [18]. Norton et al. [19] have also showed in a young population, a significant positive correlation between musical aptitude and phonemic awareness (i.e. the separation of words into phonemes), a skill essential in reading and spelling tasks. Another such study by Anvari et al. [20] found that musical ability and perception had an effect on reading ability in children even after the impact of phonemic awareness is controlled for. The relationship between musical and phonemic ability is also supported by studies on reading difficulties and musical timing skills. One such study by Overy et al. [21] carried out musical aptitude tests on children with dyslexia. Results showed that, compared to control children, those with dyslexia had reduced skills in timing, rhythm, and timbre discrimination. Different forms of auditory training, chosen on the basis of the identified deficits, have been applied to children with APD with some reported benefit in different studies [22]. Musical lessons targeted to the particular areas of deficit might be an effective and fun means of improving some of the auditory processing difficulties for this population. Finally, assessing musical skills in children with APD may help differentiate symptom profiles of this complex clinical presentation. Subjects with congenital amusia have reduced white matter in the region of the right inferior frontal gyrus on MRI [23], while Peretz et al. [24] comment on a hereditary component of amusia and hence a responsible gene. Initial results in our group of APD children showed an inverse pattern of musical deficits than that seen in the developmental disorder of congenital amusia. It may be possible that differences in brain structure, whether local or otherwise are also present in those with APD, and candidate brain regions may well be identified on the presence of specific deficits. 5. Conclusion Children with APD have been reported to have a reduced ability in and appreciation for music. The results of the present study have shown that a group of children with APD performed worse in musical aptitude tests than controls. In addition, this group displayed lower auditory processing skills in tests shown to correlate with musical aptitude measures. Assessing in detail musical skills in children with APD may further understanding of this heterogeneous condition and possibly help to determine genotype, and further research is needed.
Conflict of interest statement None. References [1] American Speech-Language Hearing Association, Evidence-based practice in communication disorders: An introduction [Technical report], 2004, http:// www.asha.org/NR/rdonlyres/B36BF8F8-C4C3-4E86-8FAD-26D76F130CBF/0/ ebpTR.pdf (retrieved 09.12.08). [2] Auditory Processing Disorder (APD) Steering Committee, British Society of Audiology. Interim position statement on APD. 2007. Retrieved December 2009 from: http://www.thebsa.org.uk/apd/Home.htm#working def. [3] J. Jerger, F. Musiek, Report of the consensus conference on the diagnosis of auditory processing disorders in school-aged children, J. Am. Acad. Audiol. 11 (2000) 467–474. [4] L. Stewart, K. von Kriegstein, J.D. Warren, T.D. Griffiths, Music and the brain: disorders of musical listening, Brain 129 (Pt 10) (2006) 2533–2553. [5] I. Peretz, M. Coltheart, Modularity of music processing, Nat. Neurosci. 6 (7) (2003) 688–691. [6] J. Ayotte, I. Peretz, K. Hyde, Congenital amusia: a group study of adults afflicted with a music-specific disorder, Brain 125 (Pt 2) (2002) 238–251. [7] T.D. Griffiths, Tone deafness: a model complex cortical phenotype, Clin. Med. 8 (6) (2008) 592–595. [8] H. Meister, H. von Wedel, M. Walger, Psychometric evaluation of children with suspected auditory processing disorders (APDs) using a parent-answered survey, Int. J. Audiol. 43 (8) (2004) 431–437. [9] E. Gordon, Musical Aptitude Profile, GIA, Chicago, 2001. [10] I. Peretz, A.S. Champod, K. Hyde, Varieties of musical disorders. The Montreal Battery of Evaluation of Amusia, Ann. N.Y. Acad. Sci. 999 (2003) 58–75. [11] D.E. Bamiou, S. Free, S. Sisodiya, F.E. Musiek, W.K. Chong, D. Gadian, K. Williamson, V. van Heyningen, A. Moore, L.M. Luxon, Auditory processing deficits and MRIdocumented brain abnormalities in children with PAX6 mutations, Arch. Pediatr. Adolesc. Med. 161 (2007) 463–469. [12] P. Dawes, D.V. Bishop, T. Sirimanna, D.E. Bamiou, Profile and aetiology of children diagnosed with auditory processing disorder (APD), Int. J. Pediatr. Otorhinolaryngol. 72 (4) (2008) 483–489. [13] British Society of Audiology, Recommended procedure for pure tone audiometry using a manually operated instrument, Br. J. Audiol. 15 (1981) 213–216. [14] F.E. Musiek, Assessment of central auditory dysfunction: the Dichotic Digit Test revisited, Ear Hear. 4 (1983) 79–83. [15] F.E. Musiek, Frequency (pitch) and duration pattern tests, J. Am. Acad. Audiol. 5 (1994) 265–268. [16] F.E. Musiek, J.A. Baran, M.L. Pinheiro, Duration pattern recognition in normal subjects and patients with cerebral and cochlear lesions, Audiology 29 (1990) 304–313. [17] J.M. Foxton, R.K. Nandy, T.D. Griffiths, Rhythm deficits in ‘tone deafness’, Brain Cogn. 62 (1) (2006) 24–29. [18] J.M. Foxton, J.B. Talcott, C. Witton, H. Brace, F. McIntyre, T.D. Griffiths, Reading skills are related to global, but not local, acoustic pattern perception, Nat. Neurosci. 6 (4) (2003) 343–344. [19] A. Norton, E. Winner, K. Cronin, K. Overy, D.J. Lee, G. Schlaug, Are there preexisting neural, cognitive, or motoric markers for musical ability? Brain Cogn. 59 (2) (2005) 124–134. [20] S.H. Anvari, L.J. Trainor, J. Woodside, B.A. Levy, Relations among musical skills, phonological processing, and early reading ability in preschool children, J. Exp. Child Psychol. 83 (2) (2002) 111–130. [21] K. Overy, A. Norton, K. Cronin, E. Winner, G. Schlaug, Examining rhythm and melody processing in young children using FMRI, Ann. N.Y. Acad. Sci. 1060 (2005) 210–218. [22] D.E. Bamiou, N. Campbell, T.S. Sirimanna, Management of auditory processing disorders, Audiol. Med. 4 (2006) 46–56. [23] K.L. Hyde, R.J. Zatorre, T.D. Griffiths, J.P. Lerch, I. Peretz, Morphometry of the amusic brain: a two-site study, Brain 129 (Pt 10) (2006) 2562–2570. [24] I. Peretz, S. Cummings, M.P. Dube´, The genetics of congenital amusia (tone deafness): a family-aggregation study, Am. J. Hum. Genet. 81 (3) (2007) 582–588.