Musician earplugs: Appreciation and protection

Recreational music exposure is a potential risk factor for noise-induced hearing loss (NIHL). Augmented hearing protectors have been designed with modified attenuation characteristics to combine hearing protection and listening comfort. However, to date, only a few independent studies have assessed the performance of those augmented protectors in realistic exposure conditions. This study compares the listening experience and temporary effects on cochlear status with different types of earplugs after exposure to contemporary club music. Five different types of commercially available hearing protectors were worn, all commonly used during leisure-time music exposure. Four of them were augmented premolded earplugs and the fifth type was an inexpensive, standard earplug frequently distributed for free at music events. During five different test sessions of 30 min each, participants not professionally involved in music wore one particular type of protector. Contemporary club music was played at sound pressure levels (SPLs) representative of concerts and bars. After each listening session, a questionnaire on sound quality and general appreciation was completed. In addition, otoacoustic emissions (OAEs) were measured directly before and after music exposure. The reported appreciation clearly differed depending on the addressed characteristics and the specific earplug type. In this test group, the reported appreciation mainly depended on comfort and looks, while differences in sound quality were less noticeable. The changes in OAE amplitude before and after noise exposure were small in terms of clinical standards. Nevertheless, the observed temporary shifts differed systematically for the different types of hearing protectors, with two types of musician earplug showing a more systematic decline than the others. Further research with respect to actual use and achieved protection for real, unsupervised music exposure is warranted.     

Hearing in young adults. Part I: The effects of attitudes and beliefs toward noise,hearing loss,and hearing protector devices

There is great concern regarding the development of noise-induced hearing loss (NIHL) in youth caused by high sound levels during various leisure activities. Health-orientated behavior of young adults might be linked to the beliefs and attitudes toward noise, hearing loss, and hearing protector devices (HPDs). The objective of the current study was to evaluate the effects of attitudes and beliefs toward noise, hearing loss, and HPDs on young adults’ hearing status. A questionnaire and an audiological test battery were completed by 163 subjects (aged 18-30 years). The questionnaire contained the Youth Attitude to Noise Scale (YANS) and Beliefs about Hearing Protection and Hearing Loss (BAHPHL). A more positive attitude or belief represented an attitude where noise or hearing loss is seen as unproblematic and attitudes and beliefs regarding HPDs is worse. Hearing was evaluated using (high frequency) pure tone audiometry (PTA), transient evoked and distortion product otoacoustic emissions. First, mean differences in hearing between the groups with different attitudes and beliefs were evaluated using one-way analysis of variance (ANOVA). Second, a χ² test was used to examine the usage of HPDs by the different groups with different attitudes and beliefs. Young adults with a positive attitude had significantly more deteriorated hearing and used HPDs less than the other subjects. Hearing conservation programs (HCPs) for young adults should provide information and knowledge regarding noise, hearing loss, and HPDs. Barriers wearing HPDs should especially be discussed. Further, those campaigns should focus on self-experienced hearing related symptoms that might serve as triggers for attitudinal and behavioral changes.     

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.     

DPOAE level mapping for detecting noise-induced cochlear damage from short-duration music exposures

Distortion product otoacoustic emission (DPOAE) level mapping provides a comprehensive picture of cochlear responses over a range of DP frequencies and f₂/f₁ ratios. We hypothesized that individuals exposed to high-level sound would show changes detectable by DPOAE mapping, but not apparent on a standard DP-gram. Thirteen normal hearing subjects were studied before and after attending music concerts. Pure-tone audiometry (500-8,000 Hz), DP-grams (0.3-10 kHz) at 1.22 ratio, and DPOAE level maps were collected prior to, as soon as possible after, and the day after the concerts. All maps covered the range of 2,000-6,000 Hz in DP frequency and from 1.3 to -1.3 in ratio using equi-level primary tone stimuli. Changes in the pure-tone audiogram were significant (P ≤ 0.01) immediately after the concert at 1,000 Hz, 4,000 Hz, and 6,000 Hz. The DP-gram showed significant differences only at f₂ = 4,066 (P = 0.01) and f₂ = 4,348 (P = 0.04). The postconcert changes were readily apparent both visually and statistically (P ≤ 0.01) on the mean DP level maps, and remained statistically significantly different from baseline the day after noise exposure although no significant changes from baseline were seen on the DP-gram or audiogram the day after exposure. Although both the DP-gram and audiogram showed recovery by the next day, the average DPOAE level maps remained significantly different from baseline. The mapping data showed changes in the cochlea that were not detected from the DP-gram obtained at a single ratio. DPOAE level mapping provides comprehensive information on subtle cochlear responses, which may offer advantages for studying and tracking noise-induced hearing loss (NIHL).     

The effects of a hearing education program on recreational noise exposure,attitudes and beliefs toward noise,hearing loss,and hearing protector devices in young adults

Excessive recreational noise exposure in young adults might result in noise-induced hearing loss (NIHL) and tinnitus. Inducing behavioral change in young adults is one of the aims of a hearing conservation program (HCP). The goal of the current study was to evaluate the effect of a hearing education program after 6 months in young adults in relation to knowledge regarding their individual hearing status. The results of a questionnaire regarding the weekly equivalent recreational noise exposure, attitudes and beliefs toward noise, and hearing loss and hearing protector devices (HPDs) were compared between both sessions. Seventy-eight young adults completed the questionnaire concerning recreational noise exposure, youth attitude to noise scale (YANS), and beliefs about hearing protection and hearing loss (BAHPHL). Their hearing status was evaluated based on admittance measures, audiometry, transient-evoked otoacoustic emissions (TEOAEs), and distortion-product otoacoustic emissions (DPOAEs). The main analysis consisted of a mixed model analysis of variance with dependent variables of either the noise exposure or the scores on (subscales of) YANS and BAHPHL. The independent variables were hearing status and session one versus session two. There was a significant decrease in recreational noise exposure and several (sub) scales of YANS and BAHPHL between both the sessions. This behavioral change resulted in a more frequent use of HPDs in 12% of the participants. However, the behavioral change was not completely related to the knowledge of young adults’ individual hearing status. To prevent hearing damage in young people, investing in HCPs is necessary, apart from regulating sound levels and its compliance at various leisure-time activities. Also, the long-term effect of HCPs and their most cost-efficient repetition rates should be further investigated.     

Joint effects of smoking, noise exposure and age on hearing loss

BACKGROUND: Smoking has been shown to have adverse effects on hearing, but it's unclear whether smoking interacts with known causes of hearing loss such as noise exposure and ageing. AIMS: To examine the hypothesis that smoking, noise and age jointly affect hearing acuity. METHODS: This cross-sectional study was carried out in 535 male adult workers of a metal processing factory. Pure-tone audiometric tests were utilized to assess hearing loss. Noise exposure assessment was based on a job exposure matrix constructed with industrial hygienist scoring and job titles. Each participant answered questionnaires about socio-demographic, life-style, occupational and health-related data. Analysis of the possible underlying biological model was undertaken assessing departures from additivity using measures of the size of the interaction present. RESULTS: Age and occupational noise exposures were, separately, positively associated with hearing loss. For all the factors combined the estimated effect on hearing loss was higher than the sum of the effects from each isolated variable, especially for smoking and noise among those 20-40 years of age, and for smoking and age among those non-exposed to occupational noise. CONCLUSIONS: The synergistic effect of smoking, noise exposure and age on hearing loss, found in this study, is consistent with the biological interaction. Furthermore, it is possible that distinct ototoxic substances in the chemical composition of mainstream smoke may synergistically affect hearing when in combination with noise exposure, which needs to be examined in future studies.     

Long-term noise exposure and the risk for type 2 diabetes: A meta-analysis

Diabetes mellitus is one of the leading causes for disability and mortality in modern societies. Apart from personal factors its incidence might be influenced by environmental risks such as air pollution and noise. This paper reports a systematic review and meta-analysis on the risk for type 2 diabetes due to long-term noise exposure. Electronic searches in MEDLINE, EMBASE and the Internet yielded 9 relevant studies (5 for residential and 4 for occupational exposure). They were checked against a predefined list of safeguards against bias producing individual quality scores, which were then fed to MetaXL to conduct a quality effects meta-analysis. People exposed at their homes to roughly L_den > 60 dB had 22% higher risk (95% confidence interval [CI]: 1.09-1.37) for type 2 diabetes in comparison to those exposed to L_den < 64 dB; when studies reporting contentious exposure categories were excluded, there was still 19% risk (95% CI: 1.05-1.35) for L_den = 60-70 dB versus L_den < 60 dB. In occupational environment there was not significant risk (relative risk [RR] = 0.91, 95% CI: 0.78-1.06) for < 85 dB versus >85 dB. There was no heterogeneity in the two groups (I² = 0.00). The results should be interpreted with caution due to methodological discrepancies across the studies; however, they are indicative of the close links that noise pollution might have not only to cardiovascular diseases but to endocrine dysfunction as well.     

Attitudes toward noise,perceived hearing symptoms,and reported use of hearing protection among college students: Influence of youth culture

The purpose of this study was to assess the attitude toward noise, perceived hearing symptoms, noisy activities that were participated in, and factors associated with hearing protection use among college students. A 44-item online survey was completed by 2,151 college students (aged 17 years and above) to assess the attitudes toward noise, perceived hearing symptoms related to noise exposure, and use of hearing protection around noisy activities. Among the participants, 39.6% experienced at least one hearing symptom, with ear pain as the most frequently reported (22.5%). About 80% of the participants were involved in at least one noise activity, out of which 41% reported the use of hearing protection. A large majority of those with ear pain, hearing loss, permanent tinnitus, and noise sensitivity was involved in attending a sporting event, which was the most reported noisy activity. The highest reported hearing protection use was in the use of firearms, and the lowest in discos/ dances. The reported use of hearing protection is associated with having at least one hearing symptom but the relationship is stronger with tinnitus, hearing loss, and ear pain (χ² = 30.5-43.5, P < 0.01) as compared to noise sensitivity (χ² = 3.8, P = 0.03); it is also associated with anti-noise attitudes, particularly in youth social events. Universities and colleges have important roles in protecting young adults’ hearing by integrating hearing conservation topic in the college curriculum, promoting hearing health by student health services, involving student groups in noise-induced hearing loss (NIHL) awareness and prevention, and establishing noise level limitations for all on-campus events.     

Predictive factors of occupational noise-induced hearing loss in Spanish workers: A prospective study

The purpose of our study was to identify the main factors associated with objective noise-induced hearing loss (NIHL), as indicated by abnormal audiometric testing, in Spanish workers exposed to occupational noise in the construction industry. We carried out a prospective study in Tenerife, Spain, using 150 employees exposed to occupational noise and 150 age-matched controls who were not working in noisy environments. The variables analyzed included sociodemographic data, noise-related factors, types of hearing protection, self-report hearing loss, and auditory-related symptoms (e.g., tinnitus, vertigo). Workers with pathological audiograms had significantly longer noise-exposure duration (16.2 ± 11.4 years) relative to those with normal audiograms (10.2 ± 7.0 years; t = 3.99, P < 0.001). The vast majority of those who never used hearing protection measures had audiometric abnormalities (94.1%). Additionally, workers using at least one of the protection devices (earplugs or earmuffs) had significantly more audiometric abnormalities than those using both protection measures simultaneously (Chi square = 16.07; P < 0.001). The logistic regression analysis indicates that the use of hearing protection measures [odds ratio (OR) = 12.30, confidence interval (CI) = 4.36-13.81, P < 0.001], and noise-exposure duration (OR = 1.35, CI = 1.08-1.99, P = 0.040) are significant predictors of NIHL. This regression model correctly predicted 78.2% of individuals with pathological audiograms. The combined use of hearing protection measures, in particular earplugs and earmuffs, associates with a lower rate of audiometric abnormalities in subjects with high occupational noise exposure. The use of hearing protection measures at work and noise-exposure duration are best predictive factors of NIHL. Auditory-related symptoms and self-report hearing loss do not represent good indicators of objective NIHL. Routine monitoring of noise levels and hearing status are of great importance as part of effective hearing conservation programs.     

Predicting and classifyng hearing loss in sailors working on speed vessels using neural networks: a field study

Background: Noise-induced hearing loss (NIHL) is one of the main risk factors affecting people''s health and wellbe-ing in the workplace. Analysing NIHL and consequently controlling the causing factors can significantly affect the improvement of working environments. Methods: One hundred and twelve male sailors participated in this study. They were classified into three groups depending on occupational noise exposure: (A) none, i.e., sound pressure level (SPL) lower than 70dBA, (B) exposed to SPL in the range of70-85dBA, and (C) exposed to SPL exceeding 80dBA. In a first phase, hearing loss shaping risk factors were identified and analysed, including hearing loss in different frequencies, age, work experience, sound pressure level (SPL), marital status, and systolic and diastolic blood pressure. Then, neural networks were trained to predict the hearing loss changes of personnel and used to determine the weight ofhearing loss factors. Finally, the accuracy of predicting models was calculated relying on Bayesian statistics. Results and conclusion: In the present study using neural networks, five models were developed. Their accuracy ranged from 92% to 100%. The frequencies of4000Hz and 2000Hz showed the strongest association with the hearing loss of the sailors. Also, including systolic and diastolic blood pressure did not have any impact on predicted hearing loss, indicating that SPL was poorly correlated with extra-auditory effects.     

Association between polymorphism of interleukin-6 in the region -174G/C and tinnitus in the elderly with a history of occupational noise exposure

Tinnitus is a symptom usually related to cochlear change that may arise from noise exposure and induces expression of proinflammatory cytokines including interleukin-6 (IL6). This study aimed to evaluate the association between the polymorphism of the IL6 gene in the region 174G/C and tinnitus in elderly with history of occupational noise exposure. Settings and Design: This was a cross-sectional study with a sample of 179 independent elderly individuals aged >60 years. Information on exposure to occupational noise was obtained by interviews. Audiological evaluation was performed using pure tone audiometry and genotyped through polymerase chain reaction by restriction fragment length polymorphism (PCR-RFLP). Data were analyzed using the chi-square test and the odds ratio (OR), with the significance level set at 5%. Among the study subjects, 24.6% were homozygous for the G allele, 39.7% were homozygous for the C allele, and 35.8% were heterozygous for IL6 (P > 0.05). Of these, 33.5% reported noise exposure history, with 42.5% having tinnitus. We found significant association between the genotype and allele frequencies of the IL6 −174 gene (rs1800795) and tinnitus among the elderly with history of exposure to occupational noise (P = 0.03). The elderly with the C allele were less likely to have tinnitus associated with history of exposure to occupational noise [OR = 0.167, confidence interval (CI) 95% 0.167-0.749; P = 0.004] when compared to those carrying the G allele. This study suggests that there is an association between polymorphisms in the IL6 gene at region – 174G/C and susceptibility to tinnitus.     

The effect of drill-generated noise in the contralateral healthy ear following mastoid surgery: The emphasis on hearing threshold recovery time

In mastoid surgeries, contralateral ear noise exposure is a known, identified factor leading to high-frequency hearing loss due to the wide variety of surgical devices that may be used during the surgery. However, the hearing threshold recovery time after this trauma was uncertain. The present study aimed to assess this time. In this prospective survival analysis study, 28 consecutive patients with chronic otitis media who were undergoing tympanomastoidectomy were assessed. Standard pure-tone audiometry (PTA) and distortion-product otoacoustic emission (DPOAE) were measured in all contralateral ears before and 6 h, 24 h, 48 h, 72 h, and 96 h after the surgery. Based on the PTA postoperative hearing loss, survival rates at frequencies of 3000 Hz, 4000 Hz, 6000 Hz, and 8000 Hz were 44.4%, 36.4%, 51.7%, and 47.4%, 24 h after surgery; 11.1%, 9.1%, 10.3%, and 13.2%, 48 h after surgery; and 0%, 0%, 3.4%, and 2.6%, 72 h after surgery, respectively. Based on the PTA and DPOAE, survival rates at all frequencies were 0%, 96 h after the surgery. According to the PTA, mean hearing recovery times were 61.98 ± 26.76 h (3000 Hz), 62.73 ± 26.50 h (4000 Hz), 67.08 ± 25.90 h (6000 Hz), 70.70 ± 24.13 h (8000 Hz), and with regard to DPOAE the recovery times were 58.58 ± 28.39 h (2000 Hz), 63.32 ± 28.83 h (4000 Hz), 65.22 ± 29.13 h (6000 Hz), and 75.14 ± 22.70 h (8000 Hz), respectively. To conclude, high-frequency hearing loss usually occurs following mastoid surgeries that is mainly temporary and reversible after 72 h.     

The impact of road traffic noise on cognitive performance in attention-based tasks depends on noise level even within moderate-level ranges

Little empirical evidence is available regarding the effects of road traffic noise on cognitive performance in adults, although traffic noise can be heard at many offices and home office workplaces. Our study tested the impact of road traffic noise at different levels (50 dB(A), 60 dB(A), 70 dB(A)) on performance in three tasks that differed with respect to their dependency on attentional and storage functions, as follows: The Stroop task, in which performance relied predominantly on attentional functions (e.g., inhibition of automated responses; Experiment 1: n = 24); a non-automated multistage mental arithmetic task calling for both attentional and storage functions (Exp. 2: n = 18); and verbal serial recall, which placed a burden predominantly on storage functions (Experiment 3: n = 18). Better performance was observed during moderate road traffic noise at 50 dB(A) compared to loud traffic noise at 70 dB(A) in attention-based tasks (Experiments 1-2). This contrasted with the effects of irrelevant speech (60 dB(A)), which was included in the experiments as a well-explored and common noise source in office settings. A disturbance impact of background speech was only given in the two tasks that called for storage functions (Experiments 2-3). In addition to the performance data, subjective annoyance ratings were collected. Consistent with the level effect of road traffic noise found in the performance data, a moderate road traffic noise at 50 dB(A) was perceived as significantly less annoying than a loud road traffic noise at 70 dB(A), which was found, however, independently of the task at hand. Furthermore, the background sound condition with the highest detrimental performance effect in a task was also rated as most annoying in this task, i.e., traffic noise at 70 dB(A) in the Stroop task, and background speech in the mental arithmetic and serial recall tasks.     

Effects of noise and acoustics in schools on vocal health in teachers

Previous studies on the influence of noise and acoustics in the classroom on voice symptoms among teachers have exclusively relied on self-reports. Since self-reported physical conditions may be biased, it is important to determine the role of objective measurements of noise and acoustics in the presence of voice symptoms. To assess the association between objectively measured and self-reported physical conditions at school with the presence of voice symptoms among teachers. In 12 public schools in Bogotá, we conducted a cross-sectional study among 682 Colombian school workers at 377 workplaces. After signed the informed consent, participants filled out a questionnaire on individual and work-related conditions and the nature and severity of voice symptoms in the past month. Short-term environmental measurements of sound levels, temperature, humidity, and reverberation time were conducted during visits at the workplaces, such as classrooms and offices. Logistic regression analysis was used to determine associations between work-related factors and voice symptoms. High noise levels outside schools (odds ratio [OR] = 1.83; 95% confidence interval [CI]: 1.12–2.99) and self-reported poor acoustics at the workplace (OR = 2.44; 95% CI: 1.88–3.53) were associated with voice symptoms. We found poor agreement between the objective measurements and self-reports of physical conditions at the workplace. This study indicates that noise and acoustics may play a role in the occurrence of voice symptoms among teachers. The poor agreement between objective measurements and self-reports of physical conditions indicate that these are different entities, which argue for inclusion of physical measurements of the working environment in studies on the influence of noise and acoustics on vocal health.     

Road,rail, and air transportation noise in residential and workplace neighborhoods and blood pressure (RECORD Study)

Associations between road traffic noise and hypertension have been repeatedly documented, whereas associations with rail or total road, rail, and air (RRA) traffic noise have rarely been investigated. Moreover, most studies of noise in the environment have only taken into account the residential neighborhood. Finally, few studies have taken into account individual/neighborhood confounders in the relationship between noise and hypertension. We performed adjusted multilevel regression analyses using data from the 7,290 participants of the RECORD Study to investigate the associations of outdoor road, rail, air, and RRA traffic noise estimated at the place of residence, at the workplace, and in the neighborhoods around the residence and workplace with systolic blood pressure (SBP), diastolic blood pressure (DBP), and hypertension. Associations were documented between higher outdoor RRA and road traffic noise estimated at the workplace and a higher SBP [+1.36 mm of mercury, 95% confidence interval (CI): +0.12, +2.60 for 65-80 dB(A) vs 30-45 dB(A)] and DBP [+1.07 (95% CI: +0.28, +1.86)], after adjustment for individual/neighborhood confounders. These associations remained after adjustment for risk factors of hypertension. Associations were documented neither with rail traffic noise nor for hypertension. Associations between transportation noise at the workplace and blood pressure (BP) may be attributable to the higher levels of road traffic noise at the workplace than at the residence. To better understand why only noise estimated at the workplace was associated with BP, our future work will combine Global Positioning System (GPS) tracking, assessment of noise levels with sensors, and ambulatory monitoring of BP.     

Pure tone hearing thresholds and leisure noise: Is there a relationship?

This paper reports on the examination of the relationship between self-reported historical noise exposure during leisure activities and audiological indicators: Measured hearing threshold levels (HTLs) and otoacoustic emissions (OAEs). The research was conducted by a cross-sectional survey of 1,432 individuals whose ages ranged from 11 years to 35 years. Methodology included a comprehensive audiometric assessment including otoscopy, pure tone audiometry (PTA) (air- and bone-conduction), OAEs, and tympanometry. A comprehensive questionnaire gathered information on demographics, hearing health status, and participation in work, nonwork, and leisure activities. Using the history of work, nonwork, and leisure noise exposure, a cumulative lifetime noise exposure was estimated. No correlation was found between cumulative lifetime noise exposure and audiometric PTA or OAE parameters.     

Effects of noise and mental task performance upon changes in cerebral blood flow parameters

The objectives of this paper were to determine whether traffic noise influences the parameters of cerebral blood flow (CBF) measured by functional transcranial Doppler sonography (fTCD) during the performance of mental tasks, and to see whether impact of noise on CBF changes with age. The study comprised 36 healthy volunteers, 22 women and 14 men, aged 25-49 years. The fTCD was performed using a fixed 2-MHz probe, aiming for an evaluation of mean velocity (MFV) and the pulsatility index (PI) in the middle cerebral artery (MCA) on both sides. Subsequently, fTCD was monitored: At rest; during performance of the Paced Auditory Serial Addition Test (PASAT); during exposure to traffic noise; and during concomitant exposure to noise and PASAT performance. MFV and PI were compared for particular conditions and correlated with age. During exposure to noise, flow parameters did not change significantly. PASAT performance in silence increased MFV and decreased PI in MCA on both sides. During PASAT performance, on exposure to noise, MCV and PI changed significantly only in the left MCA. However, values of MFV were significantly lower during noise than in silence. Correlations with age were noted for velocities in the right MCA during PASAT performance in silence and for PI on both sides during PASAT performed in noise conditions. Noise impairs the CBF during mental tasks. A comparison of changes in CBF parameters correlated with age suggests that the involvement of the nondominant hemisphere in managing with noise effects increases with age.     

噪声暴露后豚鼠皮层诱发电位的变化

采用稳态噪声100、115dB暴露于80只豚鼠,每天8小时,累积时间分别为18、96、136小时,观察皮层电反应阈的变化和恢复过程。发现100dB噪声暴露后的各时间组,在2天内听阈值完全恢复;115dB噪声暴露后的各时间组,4天内恢复较快,15天后趋于稳定,但30天仍未完全恢复。说明噪声暴露剂量是引起听损伤的重要因素,控制噪声暴露剂量应是防治噪声性耳聋的主要环节。     

噪声作业工人的畸变产物耳声发射观察

目的观察畸变产物耳声发射（DPOAE）在早期发现噪声性听力损失方面的应用价值。方法对54例非噪声作业工人（对照组）和96例纯音听阈正常的噪声作业工人（噪声组）进行纯音测听和DPOAE测试，比较两组的纯音听阈、DPOAE幅值和引出率。结果①噪声组和对照组各频率纯音听闻比较，差异无显著性（P〉0．05）；②噪声组的DPOAE幅值在3kHz、4kHz、6kHz处明显下降，与对照组比较有统计学意义（P〈0．01）；③噪声组在3kHz、4kHz和6kHz三个频率处的DPOAE引出率明显降低，与对照组比较，差异有显著性（P〈0．05，P〈0．01）：结论DPOAE能早期发现噪声性听力损失。