Artigo Original
Cláudia Giglio de Oliveira Gonçalves1 Adriana Bender Moreira Lacerda1 Bianca Simone Zeigelboim1 Jair Mendes Marques1 Débora Luders2
Descritores
Perda auditiva Música Limiar auditivo Audiometria Saúde do trabalhador Keywords
Hearing loss Music Auditory threshold Audiometry Occupational health
Correspondence adress:
Cláudia Giglio Oliveira Gonçalves R. Felisberto Fiore Dorazio, 146, Santa Felicidade, Curitiba (PR), Brasil, CEP: 82410-460.
E-mail: claudia.goncalves@utp.br
Received: 24/11/2011
Accepted: 15/10/2012
Study carried out at the Graduate Program in Communication Disorders, Universidade Tuiuti do Paraná– UTP – Tuiuti (PR), Brazil.
(1)Graduate Program in Communication Disorders, Universidade Tuiuti do Paraná – UTP – Tuiuti (PR), Brazil. (2)Speech Language Pathology and Audiology Department, Universidade Estadual do Centro-Oeste – UNICENTRO – Tuiuti (PR), Brazil.
Conlict of interests: nothing to declare.
conventional and high frequency
Limiares auditivos em músicos militares:
convencionais e altas frequências
ABSTRACT
Purpose: To analyze and characterize tonal auditory thresholds between 500 Hz and 16,000 Hz of professional musicians, speciically members of a military band. Methods: A historic cohort study was carried out comparing one group of 50 professional musicians (military band) with another group (44 subjects) without history of professional exposure to intense sound; the groups were homogenous (p<0.05%) in relation to gender (male) and age (about 35 years old). Tone threshold audiometry for conventional (from 500 to 8,000 Hz) and high frequencies was applied (from 9,000 to 16,000 Hz). Results: Exposure to music triggered permanent hearing impairment. As to conventional auditory thresholds, the exposed and non-exposed groups presented sensorineural hearing loss of 32 and 2.27%, respectively. The subjects exposed to music had 14.54 times more risks of acquiring sensorineural hearing loss than the non-exposed group. After 20 years of exposure to music, signiicant worsening was observed in auditory thresholds, especially at extended high frequencies, and differences occurred between the groups from the age of 30 on. Conclusion: Exposure to music caused permanent hearing impairment, showing differences in relation to the non-exposed group, registered in conventional audiometry and at high-frequency audiometry.
RESUMO
INTRODUCTION
For a few decades, world literature has been studying oc-cupational exposure to loud noise and deining the risks of such exposure in relation to the factors associated with the noise (intensity and time of exposure) and with the exposed subject (gender, age, among others).
The occupational exposure to music began to be studied a little after exposure to noise. It is known that music played by musical groups, such as rock, pop and jazz bands, symphonic orchestras and others, can reach high levels of sound pressure, considered harmful for the ears, which can have a negative impact on the musicians’ careers.
Studies performed with classical musicians show that the levels of sound pressure in orchestras during rehearsals or performances may range from 77 to 93 dB(A), reaching peaks of 110 dB(A)(1-3).
Researchers throughout the world described hearing disor-ders caused by exposure to music, such as hearing impairment or differences in hearing thresholds, not necessarily as disorders related to hearing loss, especially in high frequencies(3-10).
For the early diagnosis of hearing disorders among musi-cians, in order to show problems that are not yet visible in conventional audiometry, some studies have used the high-frequency audiometry (from 9,000 to 20,000 Hz) together with conventional audiometry (from 250 to 8,000 Hz)(3,8,9,11-13).
This decision is made by the audiologist, since high-frequency audiometry is an important examination to detect hearing impairment located at the base of the cochlear duct, before its characteristic effects can be detected at the conventional frequency rate(14,15).
Despite the intensiication of studies about the occupational exposure to music, the onset of hearing impairment in relation to the years of exposure to music and the inluence of the age factor on the hearing thresholds of musicians are still not clear. The purpose of this study was to analyze and characterize the tone hearing thresholds between 500 and 16,000 Hz of professional musicians from a military band.
METHODS
This is a historic cohort study which compared the hear-ing thresholds of a group of professional musicians (military band), who are daily exposed to music in rehearsals and pre-sentations, and a group with similarities as to age and gender, but with no history of professional exposure to high levels of sound pressure.
This study was approved by the Ethics Research Committee of Universidade Tuiuti do Paraná (UTP), # 14/08, and the proce-dures were performed after the signature of the informed consent form by each participant. Exclusion criteria were subjects with compromised middle ear, and two people were excluded from the group of musicians.
The group of professional musicians was comprised of 50 members of a military band in Brazil, who were daily exposed (4 hours a day) to high levels of sound pressure (music). The band is formed by wind and percussion instruments, and most of them were wind instrumentalists. The levels of sound pres-sure assessed during rehearsals by means of the integrating sound pressure level meter, placed in front of the band during the four hours of rehearsal, ranged from 90.1 to 110.3 dB(A), with mean levels of 91 to 96.3 dB(Leq).
All the musicians in the band were male, aged between 21 and 51 years (mean of 34.9 years, standard deviation of 7.8; median=34 years ) and time of band between one and 29 years (mean of 14.2 years, standard deviation of 7.7). Despite being part of a military band, the musicians joined the army to be a musician, thus not being submitted to armed training.
The group without history of occupational exposure to high levels of sound pressure had 44 subjects, all males, aged between 20 and 51 years (mean age of 35.36 years, standard deviation of 9.36; mean=34 years ). This group was com-prised of students and subjects from different professional activities who did not present high levels of sound pressure. They were all volunteers who were invited to participate in this study.
All subjects were submitted to ear canal inspection to rule out possible obstructions that could compromise the hearing test. All subjects were at acoustic rest for at least 14 hours before audiometry.
Hearing thresholds were tested by conventional audi-ometry (in frequencies of 500 to 8,000 Hz – interacoustics®
audiometry equipment, AC40 model with earphones TDH-39, calibrated according to I.S.O 389/64) and by high-frequency audiometry (from 9,000 to 16,000 Hz – AC40 audiometry equipment with KOOS/HV PRO earphones and sound in-tensity at dB hearing level – dB HL, calibrated according to the ANSI S3.6/69 pattern). The effect of age on hearing was controlled for aerial tone hearing thresholds of 500 to 8,000 Hz, using the table I.S.O 1999*.
The hearing normality criterion was deined for aerial tone hearing thresholds in up to 25 dB HL for the frequency rate of 500 to 8,000 Hz.
Statistical methods which enabled the determination of signiicant audiologic assessment results were used for data analysis, considering a 0.05 signiicance level (5%).
Descriptive statistics was applied: Student’s t-test to compare groups; Fisher’s exact test to check the correlations between audiologic examinations and the non-parametric Mann-Whitney test in the analysis of conventional tone hear-ing thresholds between groups. Kruskal-Wallis ANOVA was used to analyze tone hearing thresholds in relation to time of exposure to music. To the analysis, time of service — in years —
was grouped into three categories with ten-year interval; to the analyses considering age, there were also three categories with ten-year intervals.
RESULTS
Both groups are homogeneous in relation to mean age (Student’s t-test p=0.8128, 0.05 level), that is, there was no difference between mean ages of both groups.
The results of conventional audiometry revealed the occur-rence of sensorineural hearing disorders in 32% of the subjects (16) in the group of professional musicians and 2.27% in the group of non-musicians.
In the studied population, subjects exposed to music had 14.54 times more chances of acquiring sensorineural hearing disorders than the non-exposed group (Relative risk=14.54; 95%CI 1.9–100.5), and the excess risk attributed to exposure to music was estimated in 29 musicians out of a 100 (Attributable risk: 0.298).
Band members did not mention intense extra-occupational exposure to noise (for sports or leisure), but 23 of them per-formed activities involving music besides the military band.
Hearing thresholds of the group professionally exposed to music were analyzed in relation to time of exposure in years (Table 1).
Both ears presented differences in high frequency hear-ing thresholds (from 9,000 to 16,000 Hz) among those who have been exposed to music from one to ten years, compared to those who have been exposed to music for more than 21 years.
It was observed that both ears presented differences in hearing thresholds in the 12,500 Hz frequency, also between those exposed to music from 11 to 20 years and those exposed for more than 21 years. In the left ear, disorders in hearing thresholds between times of exposure were also for 10,000 and 14,000 Hz. As for hearing thresholds in conventional frequencies, there was a difference in 6,000 Hz in the left year between exposure rates.
For those musicians who have been exposed to music from 11 to 20 years, the frequencies of 12,500 Hz (both ears), 10,000 Hz (right ear) and 14,000 Hz (left ear) presented dif-ferences (0.05 level) in relation to those exposed for more than 21 years.
Differences in hearing thresholds were observed in some frequencies among the groups (Table 2).
In high frequencies, differences were observed in the right hear at 9,000 Hz, and bilaterally at 14,000 Hz and 16,000 Hz.
Conventional hearing thresholds between groups (exposed and non-exposed) were compared according to age group after the application of the I.S.O 1999 table (Table 3).
Most frequencies, in both ears, presented differences be-tween groups. Hearing thresholds bebe-tween groups (exposed and non-exposed) were compared according to age group by high-frequency audiometry (Table 4).
For participants aged 20 to 29 years , there were no dif-ferences between groups (Mann-Whitney test). As for the age
Table 1. Aerial tone hearing thresholds of musicians, by frequency, in relation to time of professional exposure to music (n=50)
Ear Frequency (Hz) Time of exposure (years) H-statistics p-value Differences 1 to 10 11 to 20 21 or more
Right
500 13 24 13 0.8088 0.6674
-1,000 13 24 13 2.3229 0.3275
-2,000 13 24 13 0.5122 0.7741
-3,000 13 24 13 1.3134 0.5186
-4,000 13 24 13 0.6967 0.7059
-6,000 13 24 13 3.6430 0.1618
-8,000 13 24 13 1.5146 0.4689
-9,000 13 24 13 6.5341 0.0381* (a)≠(c)
10,000 13 24 13 10.0268 0.0066* (a)≠(c)
11,000 13 24 13 9.5588 0.0084* (a)≠(c)
12,500 13 24 13 10.7432 0.0046* (a)≠(c); (b)≠(c)
14,000 13 24 13 13.2847 0.0013* (a)≠ (c)
16,000 13 24 13 13.8569 0.0010* (a)≠(c)
Left
500 13 24 13 2.4601 0.2908
-1,000 13 24 13 0.9695 0.6159
-2,000 13 24 13 1.8021 0.4061
-3,000 13 24 13 2.6808 0.2617
-4,000 13 24 13 3.5005 0.1737
-6,000 13 24 13 8.4142 0.0149* (a)≠(c)
8,000 13 24 13 3.5959 0.1656
-9,000 13 24 13 6.9201 0.0314* (a)≠(c)
10,000 13 24 13 9.8973 0.0071* (a)≠(c); (b)≠(c)
11,000 13 24 13 10.7437 0.0046* (a)≠(c)
12,500 13 24 13 12.0709 0.0024* (a)≠(c); (b)≠(c)
14,000 13 24 13 12.0487 0.0024* (a)≠(c); (b)≠(c)
16,000 13 24 13 9.3015 0.0096* (a)≠(c)
group from 30 to 39 years, differences were noticed between groups for hearing thresholds of 14,000 and 16,000 Hz, bilater-ally; in the right ear, of 2,000, 6,000 and 9,000 Hz. In the age group from 40 to 51 years old, differences between groups appeared for tone thresholds of 14,000 Hz in the right ear and 16,000 Hz in the left ear.
Among the musicians with hearing thresholds within normal-ity patterns, up to 8,000 Hz, there were signiicant differences in comparison to the group that was not exposed to music for the frequencies 14,000 Hz and 16,000 Hz in the right ear (Table 5).
DISCUSSION
This study analyzed the hearing of professional musicians (50 subjects) as compared to the hearing thresholds of a group of non-musicians (44 subjects) without history of occupational exposure to high levels of sound pressure. Both groups were
homogeneous (p<0.05) in relation to gender (male) and mean age (around 35 years old).
Hearing disorders (hearing thresholds higher than 25 dB HL) were found with characteristics of being induced by high levels of sound pressure (sensorineural hearing thresholds higher than 25 dB HL for 3,000 and/or 4,000 and/or 6,000 Hz) among musicians (32%), which means 14.54 times more chances of developing hearing disorders than participants in the group that was not exposed to music. The percentage of hear-ing disorders found in this study is similar to another analysis that assessed the hearing of percussionists, and found 39% of hearing loss and a higher proportion of hearing disorders when compared to the control group, which was equivalent in terms of gender and age(16). In a study with 329 music students (aged
between 18 and 25 years), there was no evidence of hearing loss, but of acoustic notch in 45% of the students (78% of them presented acoustic notch in 6,000 Hz and 22% in 4,000 Hz)(17). Table 3. Mean conventional tone hearing thresholds after age control by I.S.O 1999
Ear Frequency (Hz)
Exposed group Non-exposed group
p-value
n Mean SD n Mean SD
Right
500 50 8.64 7.51 44 7.41 4.40 0.3435
1,000 50 8.36 5.75 44 7.14 4.11 0.2440
2,000 50 8.12 6.28 44 5.18 4.93 0.0142*
3,000 50 8.96 8.42 44 5.64 5.23 0.0261*
4,000 50 11.48 9.63 44 6.25 5.49 0.0020*
6,000 50 10.20 8.91 44 5.68 5.53 0.0046*
8,000 50 9.98 11.46 44 5.82 6.99 0.0394*
Left
500 50 10.46 8.29 44 6.45 4.13 0.0047*
1,000 50 8.90 9.65 44 7.41 4.29 0.3467
2,000 50 10.38 10.01 44 5.95 5.36 0.0103*
3,000 50 10.36 9.14 44 5.41 4.88 0.0018*
4,000 50 13.56 11.55 44 5.91 6.35 0.0002*
6,000 50 10.94 9.76 44 6.45 5.82 0.0092*
8,000 50 8.90 11.82 44 5.43 6.18 0.0840
* Signiicant values (p≤0.05) – Mann-Whitney test
Legends: SD = standard deviation
Table 2. Demonstration of means and medians of high frequency tone hearing thresholds in groups (n=94)
Ear Frequency (Hz)
Exposed Non-exposed
p-value
n Mean Median SD n Mean Median SD
Right 9,000 50 21.7 20.0 21.5 44 13.1 12.5 9.8 0.016301*
10,000 50 23.9 20.0 15.7 44 20.7 20.0 14.0 0.304369
11,200 50 22.6 20.0 15.7 44 19.2 15.0 16.6 0.321766
12,500 50 28.6 25.0 16.4 44 28.5 20.0 20.9 0.974020
14,000 50 33.1 30.0 15.7 44 22.4 15.0 18.3 0.006109*
16,000 50 36.8 35.0 16.2 44 23.3 15.0 19.6 0.001723*
Left 9,000 50 18.2 15.0 14.1 44 15.1 15.0 11.0 0.244698
10,000 50 20.8 20.0 16.1 44 21.0 15.0 16.0 0.946674
11,200 50 21.9 20.0 16.9 44 22.0 15.0 17.6 0.967451
12,500 50 27.9 25.0 13.9 44 29.1 25.0 17.6 0.735823
14,000 50 32.6 30.0 18.1 44 24.5 22.5 17.0 0.040069*
16,000 50 33.6 30.0 16.0 44 25.4 20.0 18.9 0.052710*
Table 5. Demonstration of the mean of high-frequency thresholds in subjects of both groups with normal conventional hearing thresholds (n=77).
Ear Frequency (Hz) Exposed Non-exposed p-value
Mean SD Mean SD
Right
9,000 17.6 18.8 13.1 9.8 0.1688
10,000 20.1 10.7 20.7 14.0 0.8412
11,200 18.5 10.1 19.2 16.6 0.8092
12,500 26.8 17.0 28.5 20.9 0.6898
14,000 31.4 16.1 22.4 18.3 0.0294*
16,000 35.3 17.2 23.3 19.6 0.0093*
Left
9,000 14.4 7.1 14.4 10.1 0.9757
10,000 16.8 9.1 19.9 14.2 0.2515
11,200 18.1 11.3 20.8 15.7 0.3731
12,500 26.4 13.4 29.1 17.6 0.4575
14,000 30.4 17.7 24.5 17.0 0.1455
16,000 31.4 16.3 25.4 18.9 0.1865
* Significant values (p≤0.05) – Student’s t test Legends: SD = Standard deviation
Table 4. Tone hearing thresholds at high frequencies according to age group for both groups (n=94)
Age groups Ear Frequency (Hz) Exposed Non-exposed ca-statistics p-value
20 to 29 years old (n=25)
Right
9,000 9 16 -0.375804 0.707063
10,000 9 16 -0.171870 0.863540
11,000 9 16 0.057551 0.954106
12,500 9 16 -0.570991 0.568006
14,000 9 16 0.744622 0.456501
16,000 9 16 1.023785 0.305937
Left
9,000 9 16 -0.633693 0.526282
10,000 9 16 -0.600834 0.547951
11,000 9 16 0.257703 0.796636
12,500 9 16 -0.028533 0.977237
14,000 9 16 0.512889 0.608029
16,000 9 16 1.513717 0.130099
30 to 39 years old (n=39)
Right
9,000 26 13 2.536245 0.011205*
10,000 26 13 1.761939 0.078081
11,000 26 13 1.789652 0.073511
12,500 26 13 2.493148 0.012662*
14,000 26 13 2.917314 0.003531*
16,000 26 13 2.930032 0.003390*
Left
9,000 26 13 1.346772 0.178055
10,000 26 13 1.450503 0.146919
11,000 26 13 1.566168 0.117310
12,500 26 13 1.917599 0.055163
14,000 26 13 2.771530 0.005580*
16,000 26 13 2.847092 0.004412*
40 to 51 years old (n=30)
Right
9,000 15 15 0.178808 0.858088
10,000 15 15 0.285910 0.774947
11,000 15 15 0.197617 0.843345
12,500 15 15 1.357304 0.174686
14,000 15 15 2.166932 0.030241*
16,000 15 15 1.651194 0.098700
Left
9,000 15 15 -0.089174 0.928944
10,000 15 15 1.039544 0.298553
11,000 15 15 1.472249 0.140955
12,500 15 15 1.708635 0.087520
14,000 15 15 1.881216 0.059943
16,000 15 15 2.358893 0.018330*
Other studies also found hearing disorders among musicians, but not at high proportions; however, they observed acoustic notch in the frequencies of 4,000 or 6,000 Hz, more often than expected when compared to non-musicians, considering the same age and gender(1,3,8,9,18-20).
It was observed that hearing thresholds of musicians got worse with time of exposure to music and, in this assessed group, the longer the time of exposure (in years), the worse the hearing thresholds found in high-frequency audiometry (Table 1). Differences between hearing thresholds and time of exposure to music were clearer in the group which has been exposed for more than 21 years. However, for hearing thresholds in the frequencies 12,500 Hz (both ears), 10,000 Hz (right ear) and 14,000 Hz (left ear), differences appeared with less time of exposure to music (11 to 20 years). According to another study(21), the exposure to music at high levels, like
in bands or symphonic orchestras, leads to hearing disorders similar to that found for workers exposed to the intense noise of industries. However, this study showed that the effects of music were more perceptible after a time of exposure longer than 21 years(19). Regarding workers exposed to the intense
noise of industries, hearing loss is observed after ive to ten years of exposure to sound(10).
Comparing hearing thresholds between groups (Table 2), decreased hearing sensitivity was observed from 9,000 Hz on for both groups. Literature justiies this situation with the fact that the hearing process requires more sound energy to detect high-pitched sounds(21,22). However, when comparing tone
thresholds by high-frequency audiometry between groups, it was possible to observe that musicians presented worse hearing thresholds than the non-exposed group for the frequencies of 14,000 and 16,000 Hz in both ears, and of 9,000 Hz in the right ear. A study analyzing 187 subjects exposed to occupational noise and 52 subjects not exposed to noise reported that in the exposed group, tone hearing thresholds analyzed by high-frequency audiometry were higher than the group that was not exposed to noise, with major differences in tone thresholds involving the 14,000 Hz frequency(23). Another study(24) also
found decreased tone hearing thresholds in both ears related to the increase of high frequencies, especially from 14,000 Hz on. Other authors(20,25) found differences in hearing thresholds
between groups exposed or not to high levels of occupational sound pressure in 12,500 and 14,000 Hz frequencies; they observed that the mean of tone thresholds by high-frequency audiometry was worse when compared to the mean of tone thresholds up to 8,000 Hz, which led the authors to suggest the onset of hearing impairment in high frequencies (from 8,000 Hz on) due to the exposure to high levels of sound pressure (music).
High-frequency audiometry is recognized by some au-thors(26-29) as an important practice to monitor the hearing of
subjects exposed to high levels of sound pressure. However, in this study we observed more differences between groups for hearing thresholds in conventional frequencies (Table 3) than in high frequencies (three frequencies with differences).
Some authors(14,30) emphasize the need to control the age
variable in order to assess subjects exposed to noise at high-frequency audiometry, since age interferes in thresholds from
8,000 Hz on much more than it interferes in thresholds up to 8,000 Hz, in which the inluence of noise is more important than age. High-frequency audiometry enables the perception of hearing fatigue caused by age even before the conventional audiometry shows any signs(30). In this study, however, besides
the natural fatigue caused by age, there is also the exposure to high levels of sound pressure, which changes the hearing impairment pattern.
Therefore, when hearing thresholds were analyzed between groups, with the age controlled by the I.S.O 1999 table (Table 3), there were differences between the groups for most frequencies, in both ears. When hearing thresholds were analyzed by high-frequency audiometry, groups separated by age group (Table 4) presented differences between the groups aged 30 years old on. For those aged from 20 to 30 years, there were no differences in hearing thresholds analyzed by high-frequency audiometry.
For those aged between 30 and 39 years, hearing thresholds in the group exposed to music were worse in14,000 Hz and 16,000 Hz in both ears; and in the right ear, tone thresholds of musicians were also worse with 9,000 Hz.
For the age group between 40 and 51 years, hearing thresh-olds of subjects exposed to music were worse for the 14,000 Hz frequency in the right ear and for the 16,000 Hz frequency in the left ear, which may be related to the exposure to music.
In order to check for early signs of hearing impairment caused by exposure to music, hearing thresholds in high fre-quencies were compared to conventional tone thresholds within the normality pattern before the application of I.S.O 1999 (Table 5). Differences in tone thresholds between groups were present in the 14,000 and 16,000 Hz frequencies in the right ear. In a study with musicians presenting normal conventional audiograms, but with higher thresholds in high-frequency audiometry, an acoustic notch was observed in the 12,500 Hz frequency, bilaterally, and in the 14,000 Hz frequency, in the right ear(25). These results may suggest the onset of hearing
disorders due to the exposure to high levels of sound pressure.
CONCLUSION
Hearing thresholds of the musicians group (exposed group) presented permanent hearing disorders, thus showing dif-ferences in relation to the group that was not professionally exposed to music, registered in the conventional audiologic assessment and in the high-frequency audiometry.
The results in this study showed the need to work for the promotion of health by means of hearing conservation programs involving measures to control intense sound (collectively and individually), besides educational measures for professional musicians. Studies comparing the hearing pattern between musicians and workers exposed to noise are suggested.
REFERENCES
1. Bride D, Gill F, Proops D, Harrington M, Gardiner K, Attwell C. Noise and the classical musician. BMJ. 1992;305(6868):1561-3.
2. Nataletti P, Sisto R, Pieroni A, Sanjus F, Annesi D. Pilot study of professional exposure and hearing functionality of orchestra musicians of a national lyric theatre. G Ital Med Lav Ergon. 2007;29(3 Suppl):496-8.
3. Emmerich E, Rudel L, Richter F. Is the audiologic status of professional musicians a relection of the noise exposure in classical orchestral music? Eur Arch Otorhinolaryngol. 2008;265(7):753-8.
4. Royster JD, Royster LH, Killion MC. Sound exposures and hearing thresholds of symphony orchestra musicians. J Acoust Soc Am. 1991;89:2793-803.
5. Sataloff RT. Hearing loss in musicians. Am J Otol. 1991Mar;12(2):122-7. 6. Hellstrom PA, Axelsson A, Costa O. Temporary threshold shift induced
by music. Scan Audiol Suppl. 1998;48:87-94.
7. Mendes MH, Morata TC, Marques JM. Acceptance of hearing protection aids in members of an instrumental and voice music band. Rev Bras Otorrinolaringol. 2007;73(6):785-92.
8. Santos L, Morata TC, Jacob LC, Albizu E, Marques JM, Paini M.. Music exposure and audiological indings in Brazilian disc jockeys (DJs). Int J Audiol. 2007;46(5):223-31.
9. Jansen EJ, Helleman HW, Dreschler WA, de Laat JA. Noise induced hearing loss and other hearing complaints among musicians of symphony orchestras. Int Arch Occup Environ Health. 2009Jan;82(2):153-64. 10. Goncalves CGO, Lacerda ABM, Zocoli AMF, Oliva FC, Almeida SB,
Iantas MR. Percepção e o impacto da música na audição de integrantes de banda militar. Rev Soc Bras Fonoaudiol. 2009;14(4):515-20. 11. Dieroff HG, Schuhmann G, Meissner W, Barstsch R. Experiences with
high-frequency hearing tests in the selection of personnel for noise occupations. Laryngorhinootologie. 1991;70:594-8.
12. Arnold DJ, Lonsbury-Martin BL, Martin GK. High-frequency hearing inluences lower-frequency distortion-product otoacoustic emissions. Arch Otolaryngol Head Neck Surg. 1999;125(2):215-22.
13. Sahyeb DR, Costa Filho AO, Alvarenga KF. Audimetria de alta frequência: estudo com indivíduos audiologicamente normais. Rev Bras Otorrinolaringol. 2003;69(1):93-9.
14. Zeigelboim BS, Mangabeira-Albernaz PL, Fukuda Y. High frequency audiometry and chronic renal failure. Acta Otolaryngol. 2001;121(2):245-8. 15. Lopes AC, Otubo KA, Basso TC, Innocenti EJ, Marinelli JR, Pereira L.
Perda auditiva ocupacional: audiometria tonal X audiometria de altas frequências. Arquivos Int. Otorrinolaringol. 2009;13(3):631-7.
16. Hoffman JS, Cunningham DR, Lorenz DJ. Auditory Thresholds and factors contributing to hearing loss in a large sample of percussionists. MPPA. 2006;21(2):47-47.
17. Phillips SL, Henrich VC, Mace ST. Prevalence of noise-induced hearing loss in student musicians. Int J Audiol. 2010;49(4):309-16.
18. Kaharit KR, Axelsson A, Hellstrom PA, Zachau G. Hearing assesment of classical orchestral musicians. Scand Audiol. 2001;30(1):13-23. 19. Morais D, Benito JL, Almaraz A. Acoustic trauma in classical music
players. Acta Otorrinolaringol Esp. 2007;58(9):401-7.
20. Korres GS, Balatsouras DG, Tzagaroulakis A, Kandiloros D, Ferekidis E. Extende high-frequency audiometry in subjects exposed to occupational noise. B-ENT. 2008;4(3):147-55.
21. Zeigelboim BS, Oliveira VFBG, Marques JM, Jurkievicz AL. Limiares de audibilidade nas altas frequências em indivíduos de 20 a 30 anos com audição normal. Distúrb Comun. 2004;16(3):385-92.
22. Martinho T, Zeigelboim BS, Marques JM. Peril Audiológico nas altas frequências em indivíduos de 30 a 40 anos com audição normal. Int. Arch. Otorrinolaringol. 2005;9(1):18-25.
23. Ahmed HO, Dennis JH, Badrant O, Ismail M, Ballal SG, Ashoor A, et al. High-frequency (10 – 18kHz) hearing thresholds: reliability and effects of age and occupacional noise exposure. Occup Med (Lond). 2001;51(4):245-58. 24. Fernandes JB, Mota HB. Estudo dos limiares de audibilidade nas altas
frequências em trabalhadores expostos a ruído e solvente. Pro Fono. 2001;13(1):1-8.
25. Amorim RB, Lopes AC, Santos KTP, Melo ADP, Lauris JRP. Alterações auditivas da exposição ocupacional em músicos. Arquivos Int. Otorrinolaringol. 2008;12(3):377-83.
26. Hallmo P, Borchgevink HM, Mair IWS. Extended high-frequency thresholds in noise-induced hearing loss. Scand Audiol. 1995;24(1): 47-52.
27. Castro IFC, Conde AC, Paiva AQF, Oliveira LTN, Bernardi APA. Estudo do peril audiométrico em altas frequências em trabalhadores expostos ao ruído. Rev CEFAC. 2004;6(2):203-8.
28. Porto MAA, Gahyva DLC, Lauris JRC, Lopes AC. Avaliação da audição em frequências ultra-altas em indivíduos expostos ao ruído ocupacional. Pro Fono. 2004;16(3):237-50.
29. Somma G, Coppeta L, Magrini A, Parrella M, Cappelletti MC, Gardi S. Extended high frequency audiometry in the prevention of noise-induced hearing loss. G Ital Med Lav Ergon. 2007;29(suppl. 3):258-60. 30. Schochat E, Rabelo CM, Sanins MD. Processamento auditivo central:
