Hearing in Nonprofessional Pop/Rock Musicians

Music as a unique source of noise-induced hearing loss

Music is among the most important artistic, cultural, and entertainment modalities in any society. With the proliferation of music genres and the technological advances that allow people to consume music in any location and at any time, music over-exposure has become a significant public health issue. Music-induced hearing loss has a great deal in common with noise-induced hearing loss. However, there are important differences that make music a unique insult to the auditory system and a unique threat to public health. Its unique properties also make it a potentially valuable asset in sound conditioning paradigms. This review discusses hearing loss from noise and music, comparing and contrasting the two. Recent research on music-induced hearing loss is reviewed, followed by discussion of the differences in music-induced hearing loss between performers and consumers. The review concludes with a discussion of the potential of music as a sound conditioning stimulus to protect against acquired hearing loss.

Clinical and investigational tools for monitoring noise-induced hyperacusis

Hyperacusis is a recognized perceptual consequence of acoustic overexposure that can lead to debilitating psychosocial effects. Despite the profound impact of hyperacusis on quality of life, clinicians and researchers lack objective biomarkers and standardized protocols for its assessment. Outcomes of conventional audiologic tests are highly variable in the hyperacusis population and do not adequately capture the multifaceted nature of the condition on an individual level. This presents challenges for the differential diagnosis of hyperacusis, its clinical surveillance, and evaluation of new treatment options. Multiple behavioral and objective assays are emerging as contenders for inclusion in hyperacusis assessment protocols but most still await rigorous validation. There remains a pressing need to develop tools to quantify common nonauditory symptoms, including annoyance, fear, and pain. This review describes the current literature on clinical and investigational tools that have been used to diagnose and monitor hyperacusis, as well as those that hold promise for inclusion in future trials.

Surrounded by Sound: The Impact of Tinnitus on Musicians

AIM

To investigate the impact of tinnitus on professional musicians in the UK.

BACKGROUND

Tinnitus is the experience of sound when an external source is absent, primarily associated with the ageing process, hearing loss, and noise exposure. Amongst populations exposed to industrial noise, noise exposure and noise-induced hearing loss (NIHL) have been found to be the factors most associated with tinnitus. The risk of NIHL amongst professional musicians is greater than that amongst the general population, meaning they may be at increased risk of tinnitus.

METHODS

Seventy-four professional musicians completed an online survey involving closed and open-ended questions, and completed the Tinnitus fuctional Index (TFI) questionnaire. Descriptive statistics and thematic analysis of open-ended qualitative responses were used to analyse the data.

RESULTS

Three themes were generated from the analysis of the responses to the open-ended questions. These themes were: (1) the impact of tinnitus on the lives of professional musicians, (2) professional musician experience of tinnitus services, support, and hearing health and safety, and (3) the support professional musicians want. The mean global TFI score for professional musicians was 39.05, interpreted as tinnitus being a moderate problem. Comparisons with general population data revealed lower TFI scores for the TFI subscales of 'sense of control' and 'intrusiveness' for professional musicians and higher for auditory difficulties associated with tinnitus amongst professional musicians.

CONCLUSION

Tinnitus can negatively impact on professional musicians' lives. There is a need for bespoke self-help groups, awareness raising, and education to prevent tinnitus and promote hearing health among musicians.

Patterns of noise exposure and prevalence of hearing loss amongst Cape Town Minstrel Carnival musicians

Background

Cape Town Minstrel Carnival is one of the oldest and most authentic indigenous New Year’s customs in South Africa. Musicians who perform at this carnival are exposed to excessively loud music and therefore at a risk of acquiring noise-induced hearing loss (NIHL).

Objectives

This study aimed to determine patterns of exposure to loud music and prevalence of hearing loss amongst Cape Town Minstrel Carnival musicians.

Method

A descriptive, observational exploratory survey design was used and 43 participants (21 males and 22 females; mean age, 21 ± 9 years) took part in this study. Sound level measurements were conducted to assess musicians’ sound exposure during rehearsals and performances. All participants underwent the following audiological test battery at least 2 h before music exposure: Case history, otoscopic examination, tympanometry, pure tone audiometry and distortion products otoacoustic emission (DPOAE).

Results

Average noise levels recorded were 86 dBA during rehearsals and 98.7 dBA at performances and average durations of exposure were 240 and 10 min at rehearsals and performances, respectively. One out of 43 (1/43) participants presented with sensorineural hearing loss. Audiometric results of the remaining participants were normal and did not show a pattern suggestive of NIHL. A high proportion of participants (21/43) reported experiencing tinnitus.

Conclusion

Despite being exposed to high levels of noise, there was a low prevalence of hearing loss amongst these musicians. However, a high proportion of them reported tinnitus, which could be an indication that they were at a high risk of NIHL from the music that they played.

Loud Music and Leisure Noise Is a Common Cause of Chronic Hearing Loss, Tinnitus and Hyperacusis

High sound levels capable of permanently damaging the ear are experienced not only in factories and war zones but in concert halls, nightclubs, sports stadiums, and many other leisure environments. This review summarizes evidence that loud music and other forms of "leisure noise" are common causes of noise-induced hearing loss, tinnitus, and hyperacusis, even if audiometric thresholds initially remain within clinically normal limits. Given the huge global burden of preventable noise-induced hearing loss, noise limits should be adopted in a much broader range of settings, and education to promote hearing conservation should be a higher public health priority.

Performing Arts Medicine

Performing artists are a unique subset of athletes. With the highly repetitive nature of performance training, emphasis on proper technique, ergonomics, and preventive cross-training is vital, as many injuries are due to overuse or poor technique. There are novel medical concerns in performers, including ENT problems, mental health concerns and substance use risks. While music is central to performances, it is also a treatment modality to address cognitive, sensory, and motor dysfunctions in certain neurological conditions. Due to this wide array of issues, it is imperative to understand the specific needs and risks of performers to provide optimal medical care.

Audiological and electrophysiological assessment of professional orchestral musicians

ABSTRACT Purpose: to verify whether the frequent musical exposure can impair peripheral and central auditory pathway responses in professional orchestral musicians. Methods: 45 male individuals from 19 to 40 years old participated in the study. They were divided into two groups: one comprising 30 orchestral musicians who played strings or wind instruments, and another with 15 nonmusicians. The two groups were submitted to both conventional and high-frequency pure-tone audiometry, transient-evoked otoacoustic emissions, and frequency-following response. The results were subjected to descriptive and inferential statistical analysis, using the one-way ANOVA unmatched samples parametric test, with a 5% significance level. Results: no significant differences were observed between the hearing thresholds in both conventional and high-frequency audiometry and frequency-following response. However, there were statistically significant differences between transient-evoked otoacoustic emission responses, with lower responses to musicians in comparison to the nonmusician group. Conclusion: the results suggest that frequent musical exposure experienced by orchestral musicians can impair the cochlear hair cells’ function. Therefore, audiological monitoring is important to detect subclinical impairments.

Assisted Protection Headphone Proposal to Prevent Chronic Exposure to Percussion Instruments on Musicians

The effects of chronic exposure to high sound pressure levels (SPLs) are widely studied in the industry environment. However, the way that SPLs affect music students has not been thoroughly examined. In this paper, we study the SPL exposure of batucada students and we propose an assisted protection headphone as a part of e-health system. We measured the SPL reached during a regular percussion class. Pure-tone audiometries were performed to a set of percussion students. The gathered data were statistically analyzed. The assisted protection headphones and their operation are detailed and tested during a regular class. Our results show that 35% of the musicians present with a noise-induced hearing loss, considered as two frequencies with hearing loss of 25 dB or more or one frequency with a hearing loss of 30 dB or more. Our data also shows that those students that do not use any protection have a greater hearing loss. However, the students that use protection headphones are also suffering hearing loss. There might be a problem in the way that musicians are using the protection headphones. Our assisted protection headphones as a part of e-health measures can diminish the negative effects of percussion instruments for musicians.

Work-Related Noise Exposure in a Cohort of Patients with Chronic Tinnitus: Analysis of Demographic and Audiological Characteristics

Work-related noise exposure is one of the major factors contributing to the development of adult-onset hearing loss and tinnitus. The aim of this study was to analyze, in patients with chronic tinnitus and long-term occupational noise exposure, (A) characteristics of hearing loss, tinnitus, comorbidities, demographic characteristics and a history of work-related noise exposure and (B) differences among individuals employed in occupations with high and low risk of developing work-related noise-induced hearing loss (NIHL). One hundred thirty six patients with chronic tinnitus and at least a 10 year-long working history were divided into two groups based on the risk of their profession to induce NIHL. Individuals employed in jobs at high risk for NIHL were mostly males and exhibited a poorer hearing threshold, more evident in the left ear. Tinnitus was mostly bilateral; the next largest presentation was left-sided; patients described their tinnitus as buzzing or high-pitched. Correlation between age, length of tinnitus and worse hearing was found. Patients with a higher degree of hearing impairment were mostly males and were more likely to have a family history of hearing loss and at least one cardiovascular comorbidity. Our study shows some differences in individuals with tinnitus and a history of a profession associated with increased exposure to NIHL compared to those without such a history.

Transient evoked otoacoustic emissions in rock musicians

OBJECTIVE

Our focus in this study was the assessment of transient evoked otoacoustic emissions (TEOAEs) in a large group of rock musicians. A further objective was to analyse tinnitus among rock musicians as related to TEOAEs.

DESIGN

The study was a cross-sectional survey of rock musicians selected at random. A control group was included at random for comparison.

STUDY SAMPLE

We recruited 111 musicians and a control group of 40 non-musicians. Testing was conducted by using clinical examination, pure tone audiometry, TEOAEs and a questionnaire.

RESULTS

TEOAE SNR in the half-octave frequency band centred on 4 kHz was significantly lower bilaterally in musicians than controls. This effect was strongly predicted by age and pure-tone hearing threshold levels in the 3-6 kHz range. Bilateral hearing thresholds were significantly higher at 6 kHz in musicians. Twenty percent of the musicians had permanent tinnitus. There was no association between the TEOAE parameters and permanent tinnitus.

CONCLUSIONS

Our results suggest an incipient hearing loss at 6 kHz in rock musicians. Loss of TEOAE SNR in the 4 kHz half-octave frequency band was observed, but it was related to higher mean 3-6 kHz hearing thresholds and age. A large proportion of rock musicians have permanent tinnitus.

Hearing loss and tinnitus in rock musicians: A Norwegian survey

Our focus in this study was to assess hearing thresholds and the prevalence and characteristics of tinnitus in a large group of rock musicians based in Norway. A further objective was to assess related factors such as exposure, instrument category, and the preventive effect of hearing protection. The study was a cross-sectional survey of rock musicians selected at random from a defined cohort of musicians. A random control group was included for comparison. We recruited 111 active musicians from the Oslo region, and a control group of 40 nonmusicians from the student population at the University of Tromsø. The subjects were investigated using clinical examination, pure tone audiometry, tympanometry, and a questionnaire. We observed a hearing loss in 37.8% of the rock musicians. Significantly poorer hearing thresholds were seen at most pure-tone frequencies in musicians than controls, with the most pronounced threshold shift at 6 kHz. The use of hearing protection, in particular custom-fitted earplugs, has a preventive effect but a minority of rock musicians apply them consistently. The degree of musical performance exposure was inversely related to the degree of hearing loss in our sample. Bass and guitar players had higher hearing thresholds than vocalists. We observed a 20% prevalence of chronic tinnitus but none of the affected musicians had severe tinnitus symptomatology. There was no statistical association between permanent tinnitus and hearing loss in our sample. We observed an increased prevalence of hearing loss and tinnitus in our sample of Norwegian rock musicians but the causal relationship between musical exposure and hearing loss or tinnitus is ambiguous. We recommend the use of hearing protection in rock musicians.

Exposure to music and noise-induced hearing loss (NIHL) among professional pop/rock/jazz musicians

Noise-induced hearing loss (NIHL) has been extensively studied in industrial work environments. With the advent of new technologies, loud music has been increasingly affecting listeners outside of the industrial setting. Most research on the effects of music and hearing loss has focused on classical musicians. The purpose of the current study was to examine the relationship between the amount of experience a professional pop/rock/jazz musician has and objective and subjective variables of the musician's hearing loss. This study also examined professional pop/rock/jazz musicians' use of hearing protection devices in relation to the extent of their exposure to amplified music. Forty-four pop/rock/jazz musicians were interviewed using the Pop/Rock/Jazz Musician's Questionnaire (PRJMQ) in order to obtain self-reported symptoms of tinnitus and hyperacusis. Forty-two of the subjects were also tested for air-conduction hearing thresholds in the frequency range of 1-8 kHz. Results show that the extent of professional pop/rock/jazz musicians' exposure to amplified music was related to both objective and subjective variables of hearing loss: Greater musical experience was positively linked to higher hearing thresholds in the frequency range of 3-6 kHz and to the subjective symptom of tinnitus. Weekly hours playing were found to have a greater effect on hearing loss in comparison to years playing. Use of hearing protection was not linked to the extent of exposure to amplified music. It is recommended that further research be conducted with a larger sample, in order to gain a greater understanding of the detrimental effects of hours playing versus years playing.

Tinnitus and other auditory problems - occupational noise exposure below risk limits may cause inner ear dysfunction

The aim of the investigation was to study if dysfunctions associated to the cochlea or its regulatory system can be found, and possibly explain hearing problems in subjects with normal or near-normal audiograms. The design was a prospective study of subjects recruited from the general population. The included subjects were persons with auditory problems who had normal, or near-normal, pure tone hearing thresholds, who could be included in one of three subgroups: teachers, Education; people working with music, Music; and people with moderate or negligible noise exposure, Other. A fourth group included people with poorer pure tone hearing thresholds and a history of severe occupational noise, Industry. Ntotal = 193. The following hearing tests were used: - pure tone audiometry with Békésy technique, - transient evoked otoacoustic emissions and distortion product otoacoustic emissions, without and with contralateral noise; - psychoacoustical modulation transfer function, - forward masking, - speech recognition in noise, - tinnitus matching. A questionnaire about occupations, noise exposure, stress/anxiety, muscular problems, medication, and heredity, was addressed to the participants. Forward masking results were significantly worse for Education and Industry than for the other groups, possibly associated to the inner hair cell area. Forward masking results were significantly correlated to louder matched tinnitus. For many subjects speech recognition in noise, left ear, did not increase in a normal way when the listening level was increased. Subjects hypersensitive to loud sound had significantly better speech recognition in noise at the lower test level than subjects not hypersensitive. Self-reported stress/anxiety was similar for all groups. In conclusion, hearing dysfunctions were found in subjects with tinnitus and other auditory problems, combined with normal or near-normal pure tone thresholds. The teachers, mostly regarded as a group exposed to noise below risk levels, had dysfunctions almost identical to those of the more exposed Industry group.

Extended high-frequency thresholds in college students: effects of music player use and other recreational noise

BACKGROUND

Human hearing is sensitive to sounds from as low as 20 Hz to as high as 20,000 Hz in normal ears. However, clinical tests of human hearing rarely include extended high-frequency (EHF) threshold assessments, at frequencies extending beyond 8000 Hz. EHF thresholds have been suggested for use monitoring the earliest effects of noise on the inner ear, although the clinical usefulness of EHF threshold testing is not well established for this purpose.

PURPOSE

The primary objective of this study was to determine if EHF thresholds in healthy, young adult college students vary as a function of recreational noise exposure.

RESEARCH DESIGN

A retrospective analysis of a laboratory database was conducted; all participants with both EHF threshold testing and noise history data were included. The potential for "preclinical" EHF deficits was assessed based on the measured thresholds, with the noise surveys used to estimate recreational noise exposure.

STUDY SAMPLE

EHF thresholds measured during participation in other ongoing studies were available from 87 participants (34 male and 53 female); all participants had hearing within normal clinical limits (≤25 HL) at conventional frequencies (0.25-8 kHz).

RESULTS

EHF thresholds closely matched standard reference thresholds [ANSI S3.6 (1996) Annex C]. There were statistically reliable threshold differences in participants who used music players, with 3-6 dB worse thresholds at the highest test frequencies (10-16 kHz) in participants who reported long-term use of music player devices (>5 yr), or higher listening levels during music player use.

CONCLUSIONS

It should be possible to detect small changes in high-frequency hearing for patients or participants who undergo repeated testing at periodic intervals. However, the increased population-level variability in thresholds at the highest frequencies will make it difficult to identify the presence of small but potentially important deficits in otherwise normal-hearing individuals who do not have previously established baseline data.

Digital music exposure reliably induces temporary threshold shift in normal-hearing human subjects

OBJECTIVES

One of the challenges for evaluating new otoprotective agents for potential benefit in human populations is the availability of an established clinical paradigm with real-world relevance. These studies were explicitly designed to develop a real-world digital music exposure that reliably induces temporary threshold shift (TTS) in normal-hearing human subjects.

DESIGN

Thirty-three subjects participated in studies that measured effects of digital music player use on hearing. Subjects selected either rock or pop music, which was then presented at 93 to 95 (n = 10), 98 to 100 (n = 11), or 100 to 102 (n = 12) dBA in-ear exposure level for a period of 4 hr. Audiograms and distortion product otoacoustic emissions (DPOAEs) were measured before and after music exposure. Postmusic tests were initiated 15 min, 1 hr 15 min, 2 hr 15 min, and 3 hr 15 min after the exposure ended. Additional tests were conducted the following day and 1 week later.

RESULTS

Changes in thresholds after the lowest-level exposure were difficult to distinguish from test-retest variability; however, TTS was reliably detected after higher levels of sound exposure. Changes in audiometric thresholds had a "notch" configuration, with the largest changes observed at 4 kHz (mean = 6.3 ± 3.9 dB; range = 0-14 dB). Recovery was largely complete within the first 4 hr postexposure, and all subjects showed complete recovery of both thresholds and DPOAE measures when tested 1 week postexposure.

CONCLUSIONS

These data provide insight into the variability of TTS induced by music-player use in a healthy, normal-hearing, young adult population, with music playlist, level, and duration carefully controlled. These data confirm the likelihood of temporary changes in auditory function after digital music-player use. Such data are essential for the development of a human clinical trial protocol that provides a highly powered design for evaluating novel therapeutics in human clinical trials. Care must be taken to fully inform potential subjects in future TTS studies, including protective agent evaluations, that some noise exposures have resulted in neural degeneration in animal models, even when both audiometric thresholds and DPOAE levels returned to pre-exposure values.

Hearing loss in British Army musicians

BACKGROUND

Military musicians increasingly fulfil front line roles. Existing literature suggests that musicians are at greater risk of hearing loss than the general population. It is important to ascertain whether these findings apply to military musicians if they are to be placed in operational acoustically hazardous environments.

AIMS

To compare hearing loss between groups of British Army musicians and with their administrative (non-musician) counterparts.

METHODS

Routine health surveillance audiometric data for a group of military musicians were compared with military administrative staff during the first 8-12 years of their careers. Structured interviews were used to identify those meeting the study inclusion criteria (8 year minimum service, no significant, relevant medical history, no previous extraordinary loud noise exposure, service within study employment group throughout military career), and to clarify the instrument played.

RESULTS

Eighty-four musicians and 44 administrators participated. Using the Health & Safety Executive's (HSE's) age- and gender-correcting system, 12 (14%) musicians and 9 (20%) non-musicians had a deterioration in hearing. The overall odds ratio for developing hearing loss in musicians was 0.65 (95% CI 0.25-1.68). Compared with woodwind instrumentalists, the odds ratio for hearing loss in brass instrumentalists was 2.00 (95% CI 0.85-3.44) and for percussionists 1.83 (95% CI 0.77-2.90).

CONCLUSIONS

The findings suggest that military musicians are at no greater risk of hearing loss than their administrative counterparts after 8-12 years in service. This may represent a healthy-worker effect. There is no statistically significant differential risk of hearing loss between different instrumental groups.

Effects of chronic noise exposure on speech-in-noise perception in the presence of normal audiometry

Objective:

To assess auditory processing in noise-exposed subjects with normal audiograms and compare the findings with those of non-noise-exposed normal controls.

Methods:

Ten noise-exposed Royal Air Force aircrew pilots were compared with 10 Royal Air Force administrators who had no history of noise exposure. Participants were matched in terms of age and sex. The subjects were assessed in terms of: pure tone audiometry, transient evoked otoacoustic emissions, suppression of transient evoked otoacoustic emissions in contralateral noise and auditory processing task performance (i.e. masking, frequency discrimination, auditory attention and speech-in-noise).

Results:

All subjects had normal pure tone audiometry and transient evoked otoacoustic emissions amplitudes in both ears. The noise-exposed aircrew had similar pure tone audiometry thresholds to controls, but right ear transient evoked otoacoustic emissions were larger and speech-in-noise thresholds were elevated in the noise-exposed subjects compared to controls.

Conclusion:

The finding of poorer speech-in-noise perception may reflect noise-related impairment of auditory processing in retrocochlear pathways. Audiometry may not detect early, significant noise-induced hearing impairment.

Análise acústica em brinquedos ruidosos

OBJETIVO: analisar os níveis de ruídos emitidos por brinquedos nacionalmente comercializados, utilizados por crianças de 1 a 5 anos; comparar os valores entre os brinquedos com e sem selo do Inmetro (Instituto Nacional de Metrologia, Normalização e Qualidade Industrial) e analisar o espectro acústico dos brinquedos, com o intuito de identificar a área da cóclea que pode ser mais afetada por esses ruídos. MÉTODO: as medições foram realizadas em 20 brinquedos sonoros (10 com o selo do Inmetro e 10 sem o selo) com o uso do decibelímetro digital em sala acusticamente tratada, e a análise dos sons emitidos pelos brinquedos foi realizada por meio do programa Praat. RESULTADOS: a intensidade do ruído dos brinquedos com o selo do Inmetro posicionados a 2,5 cm do equipamento variou de 61,50 a 91,55 dB(A) e 69,75 a 95,05 dB(C) e a referente à distância de 25 cm variou entre 58,30 a 79,85 dB(A) e 62,50 a 83,65 dB(C). A intensidade do ruído dos brinquedos sem o selo do Inmetro a 2,5 cm variou entre 67,45 a 94,30 dB(A) e 65,4 a 99,50 dB(C) e na distância de 25 cm registrou desde 61,30 a 87,45 dB(A) e 63,75 a 97,60 dB(C), portanto os achados demonstraram que existem brinquedos ruidosos que ultrapassam os valores recomendados pela legislação vigente em ambos os grupos, com e sem selo do Inmetro. CONCLUSÃO: os brinquedos sem o selo do Inmetro apresentaram valores de intensidade significantemente maior em relação ao outro grupo, oferecendo maior risco à saúde auditiva das crianças.

Is there addiction to loud music? Findings in a group of non-professional pop/rock musicians

Listening to loud music may be connected to addictive behavior possibly leading to damaging effects on the cochlea. We hypothesized that members of non-professional pop/rock bands with regular exposure to loud music are more likely to show an addictive-like behavior for loud music than matched control subjects. Fifty non-professional musicians and 50 matched control subjects were asked to complete the Northeastern Music Listening Survey (NEMLS) with two basic components. The first comprises an adaptation of the validated Michigan Alcohol Screening Test (MAST) to study the addictive-like behavior towards loud music. The second comprises the criteria outlined by the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) of the American Psychiatric Society for the diagnosis of substance dependence. The NEMLS was scored using the same point system as used in the MAST.

The DSM-IV criteria for substance dependence were met by nine of the musician group and by one control subject. Seven of these nine musicians also had a positive NEMLS score. Traits of addictive-like behavior to loud music were detected more often in members of nonprofessional pop/rock bands than in control subjects.

[Hearing protectors in musicians]

The ENT physician and specialist in musician's medicine is consistently confronted with the issue of hearing protection, since musicians exposed to high sound levels due to their profession, and who are often concerned about their hearing, refer to him. Furthermore, this topic has gained more relevance since a noise exposure limit for professional musicians was issued in February 2008 by the EC guidelines for occupational health and safety regarding "Noise" (2003/10/EC). The present article gives an outline of the recent state of knowledge about sound pressure levels, hearing risks, as well as the use of hearing protection for musicians.

Relative risk of elevated hearing threshold compared to ISO1999 normative populations for Royal Australian Air Force male personnel

OBJECTIVE

This paper introduces a new method to calculate relative risks of elevated hearing thresholds, at various ages and frequencies, between a study population and ISO1999:2003: Annex A Screened, Annex B Unscreened and ISO1999 Section 5.3 adjustment for noise exposure using Annex A Screened data. We demonstrate this method on a study population of male Royal Australian Air Force personnel.

STUDY DESIGN

Using a retrospective cohort design, hearing thresholds were assessed in 583 F-111 aircraft maintenance personnel, 377 technical-trade comparisons and 492 non-technical comparisons using pure-tone audiometry. A quantile regression model was used determine whether an association exists between median hearing thresholds and F-111 maintenance, adjusting for possible confounders. The new method involves using quantile regression models with bootstrapped standard errors to estimate percentiles for the study population and thus determine the probability of a greater than 25 dB hearing threshold. This was done for the three ISO datasets as follows; for the ISO1999 Annex A screened population data the formula provided allows the calculation of these probabilities. ISO1999 Annex B unscreened population data only provides the values for the 10th, 50th and 90th percentiles at ages 30, 40, 50 and 60 only, therefore it was necessary to fit a curve to these values in order to estimate the probabilities. For ISO1999 Section 5.3 adjustment for noise exposure population we used the Annex A screened population data plus the formula. The probabilities were then divided to give the relative risks of a greater than 25 dB hearing threshold, at various ages and frequencies.

RESULTS

While no difference was observed between the three groups, the model identified a number of significant confounders, namely tinnitus, smoking, diabetes and the use of anti-depressant medications. Relative risks were high at frequencies 2 kHz and less for the study population of all ages compared to ISO A screened data. The increased relative risks at 4 and 6 kHz give the appearance of a "noise notch" for ages 30 and 40 years. The comparison with the ISO B unscreened data are significantly less than one for frequencies above 2 kHz, particularly for young men and greater than one less than 2 kHz. The relative risks for the comparison to the ISO A screened data with ISO 5.3 adjustments, are highest for young men decreasing with age, with the highest relative risk are at frequencies less than 2 kHz.

CONCLUSIONS

This paper demonstrates a new method for quantifying the probability of a clinically relevant hearing loss and the relative risk of the loss due to a risk factor. Prior to this, researchers were reduced to simplistic methods such as visual comparison of deciles which did not enable the estimation of risk. The new method can use all observed hearing thresholds per study participant, adjust for known confounding factors such age and gender, and calculate the relative risk of a clinically relevant increase in hearing threshold due to a risk factor of interest.

Audiometric records analysis in a clinical population in China

OBJECTIVE

The objective of this study was to characterize the typical hearing loss presenting at a clinical audiology center.

METHODS

Audiometric records for 8,032 cases were obtained from the database at Beijing Tongren Hospital, Capital Medical University. Based on this information, age distribution, audiometric configuration, type, degree and asymmetry of hearing loss were characterized.

RESULTS

Results showed that 48.4% of all cases of hearing loss occurred from 31 to 60 years of age, sloping hearing loss was the most common audiometric configuration, and sensorineural hearing loss dominated the type of hearing loss for both males and females. Mean pure-tone hearing thresholds revealed significant differences between genders, that is, thresholds for females were poorer than those for males from 250 to 1,000 Hz, whereas thresholds for males were poorer than those for females from 2,000 to 8,000 Hz. Analysis showed that 57.3% of audiograms showed some degree of asymmetry. No significant difference was found between genders for the average asymmetric thresholds.

CONCLUSION

This study provides the characteristics of age distribution, audiometric configuration, type, degree and asymmetry of hearing loss from a representative clinical audiology center. These data are useful for public policy efforts involving hearing loss prevention and rehabilitative program development.

Nutrient plasma levels achieved during treatment that reduces noise-induced hearing loss

Hearing loss encompasses both temporary and permanent deficits. If temporary threshold shift (TTS) and permanent threshold shift (PTS) share common pathological mechanisms, then agents that reduce PTS also should reduce TTS. Several antioxidant agents have reduced PTS in rodent models; however, reductions in TTS have been inconsistent. This study first determined whether dietary antioxidants (beta-carotene and vitamins C and E) delivered in combination with magnesium (Mg) reliably increase plasma concentrations of the active agents. Then, additional manipulations tested the hypothesis that these nutrients reduce acute TTS insult in the first 24 h after loud sound as well as longer lasting changes in hearing measured up to 7 days postnoise. Saline or nutrients were administered to guinea pigs prior to and after noise exposure. Sound-evoked electrophysiological responses were measured before noise, with tests repeated 1-h postnoise, as well as 1-day, 3-days, 5-days, and 7-days postnoise. All subjects showed significant functional recovery; subjects treated with nutrients recovered more rapidly and had better hearing outcomes at early postnoise times as well as the final test time. Thus, this combination of nutrients, which produced significant increases in plasma concentrations of vitamins C and E and Mg, effectively reduced hearing loss at multiple postnoise times. These data suggest that free radical formation contributes to TTS as well as PTS insults and suggest a potential opportunity to prevent TTS in human populations.

GABAergic neural activity involved in salicylate-induced auditory cortex gain enhancement

Although high doses of sodium salicylate impair cochlear function, it paradoxically enhances sound-evoked activity in the auditory cortex (AC) and augments acoustic startle reflex responses, neural and behavioral metrics associated with hyperexcitability and hyperacusis. To explore the neural mechanisms underlying salicylate (SS)-induced hyperexcitability and "increased central gain," we examined the effects of GABA receptor agonists and antagonists on SS-induced hyperexcitability in the AC and startle reflex responses. Consistent with our previous findings, local or systemic application of SS significantly increased the amplitude of sound-evoked AC neural activity, but generally reduced spontaneous activity in the AC. Systemic injection of SS also significantly increased the acoustic startle reflex. S-baclofen or R-baclofen, GABA-B agonists, which suppressed sound-evoked AC neural firing rate and local field potentials, also suppressed the SS-induced enhancement of the AC field potential and the acoustic startle reflex. Local application of vigabatrin, which enhances GABA concentration in the brain, suppressed the SS-induced enhancement of AC firing rate. Systemic injection of vigabatrin also reduced the SS-induced enhancement of acoustic startle reflex. Collectively, these results suggest that the sound-evoked behavioral and neural hyperactivity induced by SS may arise from a SS-induced suppression of GABAergic inhibition in the AC.

Queixas auditivas de disc jockeys da cidade de Recife

OBJETIVO: investigar a ocorrência de queixas auditivas em disc jockeys da cidade de Recife/PE. MÉTODOS: foi realizada uma entrevista com 30 disc jockeys, com idade entre 19 e 28 anos, abordando informações ocupacionais, conhecimentos gerais sobre o ruído e queixas auditivas (diminuição da acuidade auditiva, desconforto a sons intensos, zumbido, sensação de ouvido abafado e otalgia). A análise foi realizada por meio de abordagem quantitativa, utilizando o teste estatístico t-student. RESULTADOS: dentre os dados mais relevantes, destacam-se: 46,7% dos disc jockeys apresentaram, espontaneamente, queixas auditivas, em especial, a diminuição da acuidade auditiva (relatada por todos os sujeitos); 14 disc jockeys (46,67%) referiram desconforto a sons intensos e 13 (43,33%) mencionaram zumbido. Todos afirmaram ter conhecimento sobre os riscos do ruído para a saúde auditiva, mas 76,7% não realizam qualquer medida preventiva de suas consequências. A perda auditiva foi referida pelos sujeitos como o principal risco da exposição a níveis intensos de pressão sonora. CONCLUSÃO: todos os disc jockeys apresentaram queixa de perda auditiva e, entre as demais queixas auditivas, destacaram-se o desconforto a sons intensos e o zumbido. Tendo em vista a irreversibilidade da perda auditiva induzida por elevados níveis de pressão sonora, os disc jockeys devem ser periodicamente avaliados a fim de que se confirme ou não a perda auditiva de que se queixaram e, caso ela exista, deve ser monitorada para que seja passível de intervenção pelo fonoaudiólogo. Desta forma, percebe-se a necessidade de atuação da Fonoaudiologia junto aos disc jockeys, uma vez que poder-se-á propiciar a otimização do exercício profissional com o mínimo de risco possível.

[Tinnitus treatment: neurosurgical management]

Tinnitus is a very frequent symptom affecting 10% of the general population. It corresponds to the perception of an internal noise that can severely impair the quality of life. Tinnitus management requires a multidisciplinary approach in which neuromodulation and neurosurgery tend to play major roles. Classification of tinnitus separates objective tinnitus (i.e., tinnitus that can be heard or recorded) from the more frequent subjective tinnitus (i.e., tinnitus only perceived by the patient). Objective tinnitus is either pulsatile synchronous with heartbeat or asynchronous. In the former, appropriate radiological testing should search for a vascular abnormality as well as other neurological diseases (intracranial hypertension, Arnold-Chiari malformation, vascular loops, etc.). Asynchronous objective tinnitus generally corresponds to muscular contractions that require specific management. The pathophysiology of subjective tinnitus is more complex, showing strong analogies with postamputation pain syndromes. After peripheral middle ear or inner ear damage, auditory deafferentation could result in hyperactivity and/or functional reorganization within central auditory and nonauditory structures. This could explain the persistence of tinnitus after total hearing amputation (e.g., translabyrinthine approach for vestibular schwannoma) and associated symptoms such as hyperacusis or anxiety and depression. This central model finds strong support in animal experiments and in functional neuroimagery (PET, fMRI, MEG). Since no etiologically based therapies are currently available, severe subjective tinnitus management only targets tinnitus tolerance with sound enrichment or cognitive behavior therapy. However, in the near future better knowledge of tinnitus pathophysiology and innovative therapeutic tools could emerge from neuromodulation techniques such as repeated transcranial magnetic or epidural electric stimulation.

[Study of the hearing of rock and roll musicians]

BACKGROUND

rock and roll has as one of its main characteristics the excessive sound pressure levels. Several studies have demonstrated that the sound levels of rock concerts can range from 100 to 115dB (A), with peak levels of 150dB (A).

AIM

to study the hearing of rock and roll musicians, analyzing the results of the audiological evaluation and verifying the influence of time of exposure to amplified music.

METHOD

a questionnaire was answered by 23 rock and roll musicians (46 ears) who were also evaluated by means of pure tone audiometry, immitance audiometry and transient/distortion product evoked otoacoustic emissions (OAET and OAEPD).

RESULTS

regarding the time of exposure to music, values close to the limit of acceptance (tending to be significants) were found in the frequencies of 0.5 and 6kHz, in the pure tone audiometry. A statistically significant difference was also found in the OAET test in the frequency of 2kHz and also in the frequencies of 0.75, 1, 4 and 6kHz in the OAEPD test.

CONCLUSION

the results indicate that although hearing loss was not found in the studied population, alteration in the register of the OAE already exists, suggesting alteration of the cochlear function. Regarding time of exposure, the results indicate that musicians with more than 10 years of practice present statistically significant differences when compared to those with less time of exposure.

Occupationally-acquired noise-induced hearing loss: a senseless workplace hazard

OBJECTIVES

Occupational noise-induced hearing loss (ONIHL) describes an acquired hearing deficiency directly attributable to excessive workplace noise exposure. Data suggest that excessive noise attributes to approximately 37% of all adult causes of hearing loss and remains a significant contributor to employment-related morbidity internationally. Typically insidiously-acquired, often without frank progressive symptomatology, regional medical agencies continue to struggle with this potentially debilitating condition. The aim of the study was to provide a synopsis of the current understanding of ONIHL, its impact on individual workers and the wider international community, and to identify barriers to more uniform adoption of personal hearing protection.

MATERIALS AND METHODS

A review of the contemporary literature was performed using defined keyword searches and OVID, PubMed, and Google Scholar as primary electronic search engines.

RESULTS

A number of published works were identified, describing aspects of the relationship between workplace-related noise exposure and subsequent development of employee hearing impairment, which demonstrate an overwhelming gender imbalance, with up to 97% of affected individuals being male. Industry-specific associations (e.g., mining, manufacturing and heavy construction) were well documented, as were links to toxin-specific exposures, in the recognized development of hearing loss. However, evidence of integration of appraisal of the topically-current area of genetic susceptibility was often lacking. Much discordance still exists among international agencies in the prescriptive regulation and enforcement of "safe" exposure limits.

CONCLUSIONS

Despite a high level of public awareness regarding the importance of hearing preservation and increasingly stringent international occupational health, safety and welfare requirements mandating provision of safer work environments, ONIHL continues to be a significant occupational hazard. ONIHL is permanent and may cause significant disability, for which there currently exists no cure, but is largely overtly-preventable. The impact of ONIHL on the global transition toward dominant communication-rich white-collar employment roles is difficult to quantitate, but is likely to be substantive upon the afflicted individual. In the mainstream setting, exposure-avoidance strategies aimed to reduce the incidence of ONIHL remain the focus of public health and occupational medicine approaches.

Music exposure and audiological findings in Brazilian disc jockeys (DJs)

The aim of this study was to examine the music exposure and hearing of disc jockeys (DJs). We conducted personal noise dosimetry on 30 DJs and interviewed them regarding their hearing and their job. We conducted pure-tone audiometry, and transient and distortion product otoacoustic emissions before their exposure to music during their work. This first test was preceded by a period of at least 12 hours without exposure to music or noise. We repeated the pure-tone audiometry and otoacoustic emissions after their music exposure, and poorer performances were registered in all retests. The nightclubs' average sound level ranged between 93.2 to 109.7 dB(A). Statistical analysis showed significant bilateral temporary threshold shifts at all frequencies between audiometry performed pre- and post-exposure to amplified music. Transient otoacoustic emissions showed a significant difference in bilateral amplitude and reproducibility at all frequency bands tested. The comparison of distortion product otoacoustic emissions results pre- and post-music exposure showed there was a significant difference in amplitude. Music exposure was associated with temporary and permanent auditory dysfunction among professional DJs.