Limiares auditivos em músicos militares: convencionais e altas frequências

Hearing Loss, Tinnitus, Hyperacusis, and Diplacusis in Professional Musicians: A Systematic Review

Professional musicians (PMs) are at high risk of developing hearing loss (HL) and other audiological symptoms such as tinnitus, hyperacusis, and diplacusis. The aim of this systematic review is to (A) assess the risk of developing HL and audiological symptoms in PMs and (B) evaluate if different music genres (Pop/Rock Music—PR; Classical Music—CL) expose PMs to different levels of risk of developing such conditions. Forty-one articles including 4618 PMs were included in the study. HL was found in 38.6% PMs; prevalence was significantly higher among PR (63.5%) than CL (32.8%) PMs; HL mainly affected the high frequencies in the 3000-6000 Hz range and was symmetric in 68% PR PMs and in 44.5% CL PMs. Tinnitus was the most common audiological symptom, followed by hyperacusis and diplacusis. Tinnitus was almost equally distributed between PR and CL PMs; diplacusis was more common in CL than in PR PMs, while prevalence of hyperacusis was higher among PR PMs. Our review showed that PR musicians have a higher risk of developing HL compared to CL PMs; exposure to sounds of high frequency and intensity and absence of ear protection may justify these results. Difference in HL symmetry could be explained by the type of instruments used and consequent single-sided exposure.

Noise exposure and auditory thresholds of military musicians: a follow up study

Background

Military musicians are working in a noisy environment with high sound exposure levels above the international standards. Aim of the current study is to find out, whether they develop the expected hearing impairments. Adherence to the regulations for prevention in musicians is more difficult than in other occupational fields.

Methods

In an interval of 13.3 years, 36 out of 58 male military musicians of a German army music corps were subjected twice to an audiometric audit. There were no exclusion criteria apart from acute ENT infections (three musicians). These results were compared with one another and evaluated by means of statistical methods for relationships with several factors.

Results

At frequencies below 3 kHz, the follow-up audiograms were up to 5 dB better than the preliminary examination. From 4 kHz up to 8 kHz the preliminary investigations showed less hearing impairment. Averaging all frequencies the improvement of hearing ability was around 1 dB. Above 1 kHz the average hearing of the right ear was up to 7 dB better than that of the left ear. Age-induced hearing loss was 3 to 8 dB lower than predicted by ISO standards over the entire frequency range. The side of the ear (right/left) and the frequency (3, 4, and 6 kHz) were significant (p < 0.05) in hearing loss, whereas the influence of the instrument and the acoustic traumata were not.

Conclusion

Despite the high noise levels, the average hearing ability of the 36 military musicians during the investigation period only slightly deteriorated in the noise-sensitive frequencies (3, 5 and 6 kHz). Music may be less harmful than industrial noise, or the long-term auditory training of the musicians leads to a delayed presbycusis.

Amplified music exposure carries risks to hearing

OBJECTIVE

To investigate the association between changes in the outer hair cells and exposure to amplified music in a group of high-school students.

MATERIALS AND METHODS

In this retrospective, case-control study, 86 subjects underwent audiometry, immittance audiometry, and distortion-product otoacoustic emission tests. The subjects were questioned about their listening habits and divided into 2 groups: exposed and unexposed.

RESULTS

Most of the subjects had reduced function in their outer hair cells, mainly beginning at 8 kHz. Among 60 subjects-30 cases and 30 controls-75% were considered exposed and 25% unexposed. The exposed subjects were 9.33 times more likely to have altered outer hair cells than the unexposed subjects were.

CONCLUSION

Exposure to amplified music is associated with reduced function in the hair cells.

Student's music exposure: Full-day personal dose measurements

Previous studies have shown that collegiate level music students are exposed to potentially hazardous sound levels. Compared to professional musicians, collegiate level music students typically do not perform as frequently, but they are exposed to intense sounds during practice and rehearsal sessions. The purpose of the study was to determine the full-day exposure dose including individual practice and ensemble rehearsals for collegiate student musicians. Sixty-seven college students of classical music were recruited representing 17 primary instruments. Of these students, 57 completed 2 days of noise dose measurements using Cirrus doseBadge programed according to the National Institute for Occupational Safety and Health criterion. Sound exposure was measured for 2 days from morning to evening, ranging from 7 to 9 h. Twenty-eight out of 57 (49%) student musicians exceeded a 100% daily noise dose on at least 1 day of the two measurement days. Eleven student musicians (19%) exceeded 100% daily noise dose on both days. Fourteen students exceeded 100% dose during large ensemble rehearsals and eight students exceeded 100% dose during individual practice sessions. Approximately, half of the student musicians exceeded 100% noise dose on a typical college schedule. This finding indicates that a large proportion of collegiate student musicians are at risk of developing noise-induced hearing loss due to hazardous sound levels. Considering the current finding, there is a need to conduct hearing conservation programs in all music schools, and to educate student musicians about the use and importance of hearing protection devices for their hearing.

Characterization of hearing thresholds from 500 to 16,000 hz in dentists: a comparative study

Introduction High-level noise exposure in dentists' workplaces may cause damages to the auditory systems. High-frequency audiometry is an important tool in the investigation in the early diagnosis of hearing loss. Objectives To analyze the auditory thresholds at frequencies from 500 to 16,000 Hz of dentists in the city of Curitiba. Methods This historic cohort study retrospectively tested hearing thresholds from 500 to 16,000 Hz with a group of dentists from Curitiba, in the state of Paraná, Brazil. Eighty subjects participated in the study, separated into a dentist group and a control group, with the same age range and gender across groups but with no history of occupational exposure to high levels of sound pressure in the control group. Subjects were tested with conventional audiometry and high-frequency audiometry and answered a questionnaire about exposure to noise. Results Results showed that 81% of dentists did not receive any information regarding noise at university; 6 (15%) dentists had sensorineural hearing impairment; significant differences were observed between the groups only at frequencies of 500 Hz and 1,000, 6,000 and 8,000 Hz in the right ear. There was no significant difference between the groups after analysis of mean hearing thresholds of high frequencies with the average hearing thresholds in conventional frequencies; subjects who had been working as dentists for longer than 10 years had worse tonal hearing thresholds at high frequencies. Conclusions In this study, we observed that dentists are at risk for the development of sensorineural hearing loss especially after 10 years of service.