Hearing loss is a common condition among US adults, with some evidence of increasing prevalence in young adults. Noise-induced hearing loss attributable to employment is a significant source of preventable morbidity world-wide. The US military population is largely comprised of young adult males serving in a wide variety of occupations, many in high noise-level conditions, at least episodically. To identify accession and service-related risk factors for hearing-related disability, matched case-control study of US military personnel was conducted. Individuals evaluated for hearing loss disability in the US Army and Marine Corps were frequency matched to controls without history of disability evaluation on service and enlistment year. Conditional logistic regression was used to examine the association between accession and service-related factors and hearing-related disability evaluations between October 2002 and September 2010. Individuals with medically disqualifying audiograms or hearing loss diagnoses at application for military service were 8 and 4 times more likely, respectively, to have a disability evaluation related to hearing loss, after controlling for relevant accession, demographic, and service-related factors. Conservative hearing loss thresholds on pre-enlistment audiograms, stricter hearing loss medical waiver policies or qualified baseline audiograms pre-enlistment are needed in the U.S military. Industrial corporations or labor unions may also benefit from identifying individuals with moderate hearing loss at the time of employment to ensure use of personal protective equipment and engineer controls of noise.

Many studies have examined the use of portable music players portable listening devices (PLDs) from various ethnic groups. Some findings suggest that there may be differences among ethnic groups that lead to louder or longer listening when using PLD devices. For example, some studies found that Hispanic PLD users listen at higher volume levels while other studies found that African American PLD users listen at higher volume levels. No investigator has explained the reasons for differences among ethnic groups in listening intensity. This paper will address the possible reasons for these differences and offer guidelines for the prevention of noise-induced hearing loss.

In the present study, we evaluated annoyance and the effects of noise on the health of bus drivers. For that, 200 bus drivers from a public transport company participated in a cross-sectional study. Annoyance and effects on health was measured with analog scale: Sleep quality, occurrence of tinnitus, headache, irritation, and annoyance from bus engine, traffic, and passengers. Data of age and working time of bus drivers also were obtained. For noise exposure, LA _eq was evaluated in 80 buses. Statistical analysis consisted of mean, standard deviation, minimum, and maximum, Kruskal-Wallis test with post-hoc Dunn, one-way ANOVA with post-hoc Tukey and Spearman's correlation coefficient. Results indicate three groups of bus drivers (not annoyed: (N.A.), a little annoyed (L.A.) and highly annoyed (H.A.)). The group H.A. was younger and with less working time in relation to others, with a significant difference only for age. Regarding sleep quality, there was no significant difference. For results on the occurrence of tinnitus, headache and irritation after work, group H.A. had significantly higher means. Result of annoyance to the bus engine was significantly higher in H.A. than in L.A. and N.A. Annoyance to traffic and passengers, no significant differences were found, but the highest results were found for L.A., followed by H.A. and N.A. Equivalent sound pressure level in buses was above of the limit for occupational comfort. It was concluded that bus drivers has considerable level of noise annoyance and some health effects are perceived. The noise is a factor discomfort ergonomic that may cause effects on health of bus drivers. This study aims to evaluate annoyance and the effects of noise on the health of bus drivers. Cross-sectional study with buses and bus drivers. For that, 200 bus drivers from a public transport company participated in a cross-sectional study. Annoyance and effects on health was measured with analog scale: Sleep quality, occurrence of tinnitus, headache, irritation and annoyance from bus engine, traffic, and passengers. Data of age and working time of bus drivers also were obtained. For noise exposure, LA _eq was evaluated in 80 buses. Statistical analysis consisted of mean, standard deviation, minimum and maximum, Kruskal-Wallis test with post-hoc Dunn, one-way ANOVA with post-hoc Tukey and Spearman's correlation coefficient. Results indicate three groups of bus drivers (N.A., a L.A. and H.A.). The group H.A. was younger and with less working time in relation to others, with a significant difference only for age. Regarding sleep quality, there was no significant difference. For results on the occurrence of tinnitus, headache and irritation after work, group H.A. had significantly higher means. Result of annoyance to the bus engine was significantly higher in H.A. than in L.A. and N.A. Annoyance to traffic and passengers, no significant differences were found, but the highest results were found for L.A., followed by H.A. and N.A. Equivalent sound pressure level in buses was above of the limit for occupational comfort. It was concluded that bus drivers has considerable level of noise annoyance and some health effects are perceived.

The biological effects of electromagnetic waves are widely studied, especially due to their harmful effects, such as radiation-induced cancer and to their application in diagnosis and therapy. However, the biological effects of sound, another physical agent to which we are frequently exposed have been considerably disregarded by the scientific community. Although a number of studies suggest that emotions evoked by music may be useful in medical care, alleviating stress and nociception in patients undergoing surgical procedures as well as in cancer and burned patients, little is known about the mechanisms by which these effects occur. It is generally accepted that the mechanosensory hair cells in the ear transduce the sound-induced mechanical vibrations into neural impulses, which are interpreted by the brain and evoke the emotional effects. In the last decade; however, several studies suggest that the response to music is even more complex. Moreover, recent evidence comes out that cell types other than auditory hair cells could response to audible sound. However, what is actually sensed by the hair cells, and possible by other cells in our organism, are physical differences in fluid pressure induced by the sound waves. Therefore, there is no reasonable impediment for any cell type of our body to respond to a pure sound or to music. Hence, the aim of the present study was to evaluate the response of a human breast cancer cell line, MCF7, to music. The results' obtained suggest that music can alter cellular morpho-functional parameters, such as cell size and granularity in cultured cells. Moreover, our results suggest for the 1 ^st time that music can directly interfere with hormone binding to their targets, suggesting that music or audible sounds could modulate physiological and pathophysiological processes.

Distortion product otoacoustic emission (DPOAE) level mapping may be useful for detecting noise-induced hearing loss (NIHL) early. Employing DPOAE mapping effectively requires knowledge of the optimal mapping parameters to use for detecting noise-induced changes. The goal of this project was to show the map regions that differ most between normal and noise-damaged cochlea to determine the optimal mapping parameters for detecting NIHL. DPOAE level maps were generated for the 2f ₁ -f ₂ and the 2f ₂ -f ₁ DPOAEs for 17 normal hearing male subjects and 19 male subjects with NIHL. DPOAEs were measured in DPOAE frequency steps of approximately 44 Hz from 0.5 kHz to 6 kHz using constant f ₂ /f ₁ ratios incremented in 0.025 steps from 1.025 to 1.5 using both unequal-level (L1,L2 = 65,55 dB sound pressure level (SPL)) and equi-level (L1,L2 = 75,75 dB SPL) stimulus paradigms. Maximal responses for the 2f ₂ -f ₁ emission at L1,L2 = 65,55 dB SPL were found at lower ratios compared to previous studies. The map regions where NIHL eliminated or reduced DPOAE magnitude were identified. DPOAE level mapping using higher-level, equi-level primaries produced significantly more detectable emissions particularly for the 2f ₂ -f ₁ emission. The data from this study can be used to optimize DPOAE level mapping parameters for tracking noise-exposed subjects longitudinally.

This work considers an alternate methodology for the estimation of the noise exposed population of the Australian workforce. Previous methods relied on the statistics from the annual rate of application for worker's hearing loss compensation claims, the generalization of small scale surveys to the broader population or larger scale telephone surveys. This proposed method takes measured noise exposure data from sampled industries and combines that with official demographic information on the numbers employed in the respective industries. From the Australian data, it is estimated that around 20.1% of the workforce regularly work in noise above the recommended exposure standard (L _{Aeq, 8 h} = 85 dB) and 9.4% above and exposure of 90 dB. These figure lie within the range of estimates derived from other methodologies.

Based on a previously published exposure-effect model of Electroencephalography (EEG)-awakening reactions (AWR) due to nightly church bell noise events, as well as on geocoded building and population data, we estimated the total number of the church bell noise induced awakenings on the population of the Canton of Zurich, in Switzerland. The calculated mean number of EEG awakenings per person in the studied region, triggered by church bell ringing, varied between 0 and about 5.5 per night. The results suggest that up to 120-150 m distance from churches, on average more than one additional EEG awakening occurs per night per person. An estimated 2.5-3.5 percent of the population in the Canton of Zurich experiences at least one additional awakening per night due to church bell noise. To provide a simple decision support tool for authorities that consider limiting bell ringing in the night in some form, we simulated different scenarios to estimate the effects of different sound attenuation measures at the belfry as well as the effects of different lengths and positions of nocturnal bell ringing suspension periods. The number of awakenings could be reduced by more than 99 percent by, for example, suspending church bell ringing between midnight and 06 h in the morning. A reduction of the number of AWRs of about 75 percent could be achieved by reducing the sound-pressure levels of bells by 5 dB.

Preceding research has linked noise exposure, road traffic bring the dominant community source, with annoyance, which is an indicator of more serious, chronic health conditions. This study aimed to explore the association between residential road traffic noise and self-reported annoyance from an adult Indian population, residing close to roadways. The cross-sectional study used a questionnaire survey in an urban Indian municipality along roadways, where faηade noise assessment was made manually. The survey included randomly selected subjects aged 19-59 years, residing minimum of 10 years in the area and residing within 50 m of the roadways. Association of self-reported annoyance and noise exposure was examined by binary and multiple logistic regressions. The noise exposure was classified in units of 5 dB (A) from <65 dB (A) to 80 dB (A). Self-reported annoyance was marked at levels above 65-70 dB (A). A 67.5 dB (AA) is suggested as a threshold level. The association was statistically significant for female subjects with the adjusted odds ratio being 2.35 (95% confidence intervals: 0.99-5.58). Prevalence of annoyance was more for male subjects. Both age and period of residence were significant predictors of annoyance. Vulnerable age sub-groups were 34-40 years, followed by 50-60 years. The results of this study further suggest the association residential noise exposure near roadways and self-reported annoyance, among the study subjects.

The aim of the present study was to compare the adolescents' attitudes toward loud music in relation to a set of self-perceived auditory symptoms and psychological variables such as norms, preparedness to take risks and risk-judgment in noisy situations. A questionnaire on hearing and preventive behavior was distributed to 281 upper secondary school students aged 15-19 years. The questionnaire included youth attitude to noise scale, questions about perceived hearing symptoms such as tinnitus and sound sensitivity and finally statements on perceived behavioral norms regarding hearing protection use, risk-taking and risk-judgment in noisy settings. Self-perceived auditory symptoms such as sound sensitivity and permanent tinnitus had a significant relationship with less tolerant attitudes toward loud music. Permanent tinnitus and sound sensitivity together accounted for 15.9% of the variation in attitudes toward loud music. Together with the psychological variables norms, preparedness to take risks and risk-judgment 48.0% of the variation in attitudes could be explained. Although perceived hearing symptoms (sound sensitivity and permanent tinnitus) was associated with less tolerant attitudes toward loud music, psychological variables such as norms, preparedness to take risks and risk-judgment were found to be more strongly associated with attitudes toward loud music and should therefore be considered more in future preventive work. Health promotive strategies should focus on changing not merely individual attitudes, but also societal norms and regulations in order to decrease noise induced auditory symptoms among adolescents.

Traffic noise is considered causing annoyance and severe health effects like cardiovascular disease (CVD). The present laboratory study examines the importance of individual factors, namely age, gender and personality traits on short term physiological and affective response to vehicle pass-by noises. Four groups of subjects (20-30 vs. 40-55 year-old male or female, n = 66 in total) were exposed to a series of vehicle pass-by noises. Physiological responses (finger-pulse amplitude [FPA], skin conductance level [SCL]) were registered during the exposure; affective responses and judgements regarding the sounds were assessed by questionnaires. Noise sensitivity and sensation seeking were measured by validated questionnaires. The results show different patterns of response depending on age, gender and personality. The strongest sympathetic stress reaction as measured by SCL was found for the older female group. In regression analysis, the SCL response was predicted by the female gender and low score of sensation seeking only (adjusted R² = 0.139). The FPA response was strongest among the young men and age was the only significant predictor. For affective responses of pleasantness and activation, regression analysis proved noise sensitivity and sensation seeking to be significant predictors (adjusted R² = 0.187 respectively 0.154). Age, gender and personality influence physiological and affective reactions to traffic noise, which might affect health conditions. Especially, a potential risk of older women for CVD owing to noise should be investigated further. Individual sensitiveness in terms of noise sensitivity or sensation seeking proves to be important for explaining differences in response to noise.

The aim of the present research is to provide a user-friendly index of the relative impairment associated with noise in the aircraft cabin. As such, the relative effect of noise, at a level typical of an aircraft cabin was compared with varying levels of alcohol intoxication in the same subjects. Since the detrimental effect of noise is more pronounced on non-native speakers, both native English and non-native English speakers featured in the study. Noise cancelling headphones were also tested as a simple countermeasure to mitigate the effect of noise on performance. A total of 32 participants, half of which were non-native English speakers, completed a cued recall task in two alcohol conditions (blood alcohol concentration 0.05 and 0.10) and two audio conditions (audio played through the speaker and noise cancelling headphones). The results revealed that aircraft noise at 65 dB (A) negatively affected performance to a level comparable to alcohol intoxication of 0.10. The results also supported previous research that reflects positively on the benefits of noise cancelling headphones in reducing the effects of noise on performance especially for non-native English speakers. These findings provide for personnel involved in the aviation industry, a user-friendly index of the relative impairment associated with noise in the aircraft cabin as compared with the effects of alcohol. They also highlight the benefits of a simple countermeasure such as noise cancelling headphones in mitigating some of the detrimental effects of noise on performance.