The Combined Effect of Elevated Blood Pressure and Occupational Noise Exposure on Bilateral High-Frequency Hearing Loss: Evidence From a Large Sample Cross-sectional Study.

BACKGROUND: Combined effect of elevated blood pressure and occupational noise exposure on hearing loss have rarely been evaluated among Chinese population. METHODS: This cross-sectional study was conducted in 242,811 participants. Logistic regression model was performed to estimate the independent and combined associations. RESULTS: Compared with participants without occupational noise exposure, the risk of bilateral high-frequency hearing loss (BHFHL) was significantly higher for noise exposure 10 years or more (odds ratio [OR] = 1.29, 95% confidence interval [95% CI] = 1.23-1.35). Compared with no hypertension, participants with grade 1 hypertension had higher risk of BHFHL in all age groups (OR, 1.14; 95% CI, 1.09-1.20). As to the combined effect, the highest BHFHL risk was found in males (OR, 1.51; 95% CI, 1.37-1.67), especially among participants with grade 1 hypertension older than 50 years (OR, 1.65; 95% CI, 1.46-1.88). CONCLUSIONS: Elevated blood pressure may synergistically influence hearing loss combined with occupational noise exposure.

Bilateral high-frequency hearing loss is associated with elevated blood pressure and increased hypertension risk in occupational noise exposed workers.

OBJECTIVE: To investigate the association of bilateral high-frequency hearing loss (BHFHL) with blood pressure and hypertension among occupational noise exposed workers. METHODS: Occupational noise exposed workers were enrolled in 2017 from the occupational diseases survey of Chengdu. BHFHL was classified as normal, mild, or high by the bilateral high-frequency tone average. Linear regression model was used to assess the effects of occupational noise exposure time and BHFHL on blood pressure. Logistic regression model was performed to estimate hypertension risk odds ratios (ORs) associated to occupational noise exposure time and BHFHL. RESULTS: Increasing years of occupational noise exposure and BHFHL were significantly associated with systolic and diastolic blood pressure increase (all P<0.001). The lineal trend was only significant in males, with adjusted ORs for hypertension gradually increasing with increasing years of occupational noise exposure (P<0.001). Furthermore, subjects having mild and high BHFHL had a higher hypertension risk of 34% and 281%, respectively (both P<0.001). Dose-response relationship between BHFHL and hypertension was found in both males and females. CONCLUSIONS: Occupational noise exposure was positively associated with blood pressure levels and hypertension risk.

Noise exposure and hearing status among call center operators.

INTRODUCTION: The overall objective of the study was to assess noise exposure and audiometric hearing threshold levels (HTLs) in call center operators. MATERIALS AND METHODS: Standard pure-tone audiometry and extended high-frequency audiometry were performed in 78 participants, aged 19 to 44 years (mean ± standard deviation: 28.1 ± 6.3 years), employed up to 12 years (2.7 ± 2.9 years) at one call center. All participants were also inquired about their communication headset usage habits, hearing-related symptoms, and risk factors for noise-induced hearing loss (NIHL). Noise exposure under headsets was evaluated using the microphone in a real ear technique as specified by ISO 11904-1:2002. The background noise prevailing in offices was also measured according to ISO 9612:2009. RESULTS AND DISCUSSION: A personal daily noise exposure level calculated by combining headset and nonheadset work activities ranged from 68 to 79 dBA (74.7 ± 2.5 dBA). Majority (92.3%) of study participants had normal hearing in both ears (mean HTL in the frequency range of 0.25-8 kHz ≤20 dB HL). However, their HTLs in the frequency range of 0.25 to 8 kHz were worse than the expected median values for equivalent highly screened otologically normal population, whereas above 8 kHz were comparable (9-11.2 kHz) or better (12.5 kHz). High-frequency hearing loss (mean HTLs at 3, 4, and 6 kHz >20 dB HL) and speech-frequency hearing loss (mean HTLs at 0.5, 1, 2, and 4 kHz >20 dB HL) were noted in 8.3% and 6.4% of ears, respectively. High-frequency notches were found in 15.4% of analyzed audiograms. Moreover, some of call center operators reported hearing-related symptoms. CONCLUSIONS: Further studies are needed before firm conclusions concerning the risk of NIHL in this professional group can be drawn.

Extended high-frequency hearing loss following the first episode of otitis media.

OBJECTIVES/HYPOTHESIS: Otitis media has been associated with several auditory and developmental sequelae. Here, the results of auditory tests were evaluated in patients who had a first episode of unilateral otitis media and compared with the contralateral healthy ear. STUDY DESIGN: Cohort study. METHODS: This study was undertaken from 2015 to 2016, with a follow-up period of 6 months. RESULTS: A total of 41 patients who had been diagnosed with unilateral acute otitis media were selected. Standard (250 Hz-8 kHz) and extended high-frequency (8 kHz-16 kHz) audiometry was performed within 5 days of the beginning of the clinical symptoms, and then in defined time frames for a period of 6 months. The results of the contralateral healthy ears were used as individual controls. After closure of the initial air-bone gap, the results of the standard audiometry did not demonstrate significant differences in the thresholds of diseased ears compared with controls. A significant elevation of the mean extended high-frequency thresholds in the ears affected by otitis media was observed at the first and subsequent appointments within the 6-month follow-up period. Diseased ears from patients who experienced tinnitus during the 6-month follow-up period had significantly higher thresholds in the extended high frequencies than diseased ears from patients without residual tinnitus. CONCLUSIONS: These results suggest that the first episode of otitis media may lead to persistent elevation of the mean thresholds of extended high-frequencies, whereas persistent tinnitus after 6 months of the acute infection is associated with more severe hearing loss. LEVEL OF EVIDENCE: 2b Laryngoscope, 128:2879-2884, 2018.

Association Between Portable Music Player Use and Hearing Loss Among Children of School Age in the Netherlands.

Importance: Portable music player use may have harmful effects on hearing. The magnitude and effect of frequent music exposure, especially at younger ages, on hearing are unclear. Objectives: To examine the prevalence of noise-induced hearing loss in a 9- to 11-year-old population and associations with portable music player use and sociodemographic factors. Design, Setting, and Participants: A cross-sectional study within an ongoing, prospective, birth cohort study within Rotterdam, the Netherlands was conducted. Between ages 9 and 11 years, 5355 children underwent their first audiometric evaluation. Children were excluded if they had missing or failed tympanometry results. The study was conducted from April 16, 2012, to October 25, 2015. Exposures: Portable music player (PMP) use and sociodemographic factors assessed via parental questionnaires. Main Outcomes and Measures: Hearing acuity measured by pure-tone audiometry at 0.5 to 8 kHz. Possible noise-induced hearing loss was contingent on a high-frequency notch and/or high-frequency hearing loss in the audiogram, or reported hearing-related symptoms. Results: The final sample included 3116 participants who were a mean (interquartile range) age of 9.7 (9.6-9.9) years and equally distributed between boys (1550 [49.7%]) and girls (1566 [50.3%]). Of these, 1244 (39.9%) reported no PMP use, 577 (18.5%) reported use 1 or 2 days per week, 254 (8.2%) reported use 3 or more days per week, and for 1041 (33.4%), PMP use was not reported. Audiometric notches and high-frequency hearing loss were present in 443 (14.2%) of all children; 140 (4.5%) fulfilled the criteria of a notch, 238 (7.6%) of high-frequency hearing loss, and 65 (2.1%) of both. Of the cohort, 52 (1.7%) showed bilateral impairment. Hearing-related symptoms were reported for 232 (11.3%) of the respondents, and 831 (40.0%) of the respondents used portable music players. Portable music player use was associated with high-frequency hearing loss (odds ratio [OR], 2.88; 95% CI, 1.36-6.980 for 1 or 2 days per week and OR, 2.74; 95% CI, 1.22-6.96 for ≥3 days per week), but listening time and duration were not. There was no association of music exposure with high-frequency notches. Conclusions and Relevance: In this study, 14.2% of school-aged children showed audiometric notches or high-frequency hearing loss. This hearing impairment is already present prior to exposure to known noise hazards, such as club and concert attendance, and may have lifelong consequences. Repeated measurements are needed to confirm the association of portable music player use with hearing impairment in children.

Patterns of Extended High-frequency Hearing Loss Following Stapes Surgery.

OBJECTIVE: Thresholds in the extended high-frequency (EHF) range (> 8 kHz) often worsen after otherwise successful stapedectomy. The aims of this study were to document the prevalence of hearing loss from 0.25 to 16 kHz after stapedectomy and the relative rates of transient and permanent EHF hearing loss. STUDY DESIGN: Prospective, observational, longitudinal. SETTING: Tertiary referral center. PATIENTS: Thirty-nine patients who underwent 44 primary or revision stapes surgeries. INTERVENTION: Hearing thresholds were measured at 0.25 to 16 kHz preoperatively, and at approximately 1 week, 1, 3, 6, and 12 months postoperatively. MAIN OUTCOME MEASURES: Average threshold changes in bands of frequencies (0.25-1, 2-8, 9-11.2, 12.5-16 kHz) and the percentage of patients with a change in the highest frequency at which a hearing threshold could be measured were evaluated at each assessment. RESULTS: A mean hearing loss was documented in the EHF range at all postoperative assessments. There was a decrease in the highest frequency at which a hearing threshold was measureable in 77% of patients at the first postoperative assessment, and despite some improvement over time, in 50% of patients 12 months postoperatively. CONCLUSION: There is a significant incidence of EHF loss after stapedectomy. Although partial recovery often occurs, more than half of patients retain an EHF hearing loss 12 months postoperatively. As hearing loss in the EHF range is more common than loss at 4 kHz, EHF measurements may be a more sensitive model to compare surgical factors and evaluate pharmacologic interventions.

Laboratory evaluation of an optimised internet-based speech-in-noise test for occupational high-frequency hearing loss screening: Occupational Earcheck.

OBJECTIVE: The "Occupational Earcheck" (OEC) is a Dutch online self-screening speech-in-noise test developed for the detection of occupational high-frequency hearing loss (HFHL). This study evaluates an optimised version of the test and determines the most appropriate masking noise. DESIGN: The original OEC was improved by homogenisation of the speech material, and shortening the test. A laboratory-based cross-sectional study was performed in which the optimised OEC in five alternative masking noise conditions was evaluated. STUDY SAMPLE: The study was conducted on 18 normal-hearing (NH) adults, and 15 middle-aged listeners with HFHL. RESULTS: The OEC in a low-pass (LP) filtered stationary background noise (test version LP 3: with a cut-off frequency of 1.6 kHz, and a noise floor of -12 dB) was the most accurate version tested. The test showed a reasonable sensitivity (93%), and specificity (94%) and test reliability (intra-class correlation coefficient: 0.84, mean within-subject standard deviation: 1.5 dB SNR, slope of psychometric function: 13.1%/dB SNR). CONCLUSIONS: The improved OEC, with homogenous word material in a LP filtered noise, appears to be suitable for the discrimination between younger NH listeners and older listeners with HFHL. The appropriateness of the OEC for screening purposes in an occupational setting will be studied further.

Is There a Relationship Between Obstructive Sleep Apnea (OSA) and Hearing Loss?

BACKGROUND Obstructive sleep apnea (OSA) is a common disorder with an estimated prevalence in the general population of 2-5%. Its main clinical features are loud snoring and breathing stoppage during sleep. Ischemia could be a consequence of noise-induced hearing loss because cochlear oxygen tension is reduced during and after noise exposure. In this study, we evaluated auditory function in patients affected by OSA and simple snoring. MATERIAL AND METHODS A total of 66 participants (male to female ratio: 40:26) were included in the study, of which 21 were in the control group, 18 were in the simple snoring group, and 27 were in the OSA patient group. Polysomnography and audiometric examination were performed in all participants. RESULTS The mean ages of the participants in the control, simple snoring, and OSA groups were 39.14±9.9, 37.28±8.2, and 41.56±8.99 years, respectively. There were no statistically significant differences among groups regarding age or sex; however, there were statistically significant differences among groups in body mass index, apnea-hypopnea index scores, mean saturation, and duration under 90% saturation. In addition, statistically significant differences were found between the patient group and the control and simple snoring groups concerning the mean saturation, duration under 90% saturation, and the extended high frequency of hearing. CONCLUSIONS These data show that snoring may cause hearing loss at extended high frequencies.

Exposed, but Not Protected: More Is Needed to Prevent Drug-Resistant Tuberculosis in Healthcare Workers and Students.

"Occupational MDR-TB"  …  "XDR-TB"  …  "Treatment-induced hearing loss": 3 life-changing messages imparted over the phone. Three personal accounts are shared highlighting the false belief held by many healthcare workers (HCWs) and students in low-resource settings-that they are immune to tuberculosis despite high levels of occupational tuberculosis exposure. This misconception reflects a lack of awareness of tuberculosis transmission and disease risk, compounded by the absence of accurate occupational tuberculosis estimates. As the global problem of drug-resistant (DR) tuberculosis evolves, HCWs are increasingly infected and suffer considerable morbidity and mortality from occupational DR tuberculosis disease. Similarly, healthcare students are emerging as a vulnerable and unprotected group. There is an urgent need for improved detection, vaccines, preventive therapy, treatment, and support for affected HCWs and those they care for, as well as destigmatization of all forms of tuberculosis. Finally, efforts to protect HCWs and prevent DR tuberculosis transmission by universal implementation of tuberculosis infection control measures should be prioritized.

Expression of amyloid-ß in mouse cochlear hair cells causes an early-onset auditory defect in high-frequency sound perception.

Increasing evidence indicates that defects in the sensory system are highly correlated with age-related neurodegenerative diseases, including Alzheimer's disease (AD). This raises the possibility that sensory cells possess some commonalities with neurons and may provide a tool for studying AD. The sensory system, especially the auditory system, has the advantage that depression in function over time can easily be measured with electrophysiological methods. To establish a new mouse AD model that takes advantage of this benefit, we produced transgenic mice expressing amyloid-ß (Aß), a causative element for AD, in their auditory hair cells. Electrophysiological assessment indicated that these mice had hearing impairment, specifically in high-frequency sound perception (>32 kHz), at 4 months after birth. Furthermore, loss of hair cells in the basal region of the cochlea, which is known to be associated with age-related hearing loss, appeared to be involved in this hearing defect. Interestingly, overexpression of human microtubule-associated protein tau, another factor in AD development, synergistically enhanced the Aß-induced hearing defects. These results suggest that our new system reflects some, if not all, aspects of AD progression and, therefore, could complement the traditional AD mouse model to monitor Aß-induced neuronal dysfunction quantitatively over time.

Exposure to loud noise, bilateral high-frequency hearing loss and coronary heart disease.

OBJECTIVES: Bilateral high-frequency hearing loss is an indicator for chronic exposure to loud noise. This study aimed to examine the association between bilateral high-frequency hearing loss and the presence of coronary heart disease (CHD). METHODS: This study included 5223 participants aged 20-69 years who participated in the audiometry examination of the National Health and Nutrition Examination Survey 1999-2004. Bilateral high-frequency hearing loss was defined as the average high-frequency (3, 4 and 6 kHz) hearing threshold ≥25 dB in both ears. CHD was defined as self-reported diagnoses by doctors or other health professionals. RESULTS: Compared with those with normal high-frequency hearing, participants with bilateral high-frequency hearing loss were more likely to have CHD (OR 1.91; 95% CI 1.28 to 2.85) after adjustment for various covariates. This association was particularly strong for currently employed workers who were exposed to loud occupational noise (OR 4.23; 95% CI 1.32 to 13.55). For this subgroup, there was no significant association of CHD with unilateral high-frequency hearing loss, and unilateral or bilateral low-frequency hearing loss. Furthermore, there was no significant association of CHD with any types of hearing loss for participants who were not exposed to loud noise. Stratified analyses for participants exposed to loud noise showed that the observed association was particularly strong for those who were less than 50 years of age, less educated and current smokers. CONCLUSIONS: On the basis of an objective indicator for personal chronic exposure to loud noise, this study confirmed that exposure to loud occupational noise is associated with the presence of CHD.

Shooting history and presence of high-frequency hearing impairment in swedish hunters: A cross-sectional internet-based observational study.

The aim of this cross-sectional study among Swedish hunters was to examine the association between shooting history and presence of high-frequency hearing impairment (HFHI). All hunters registered with an e-mail address in the membership roster of the Swedish Hunters' Association were invited via e-mail to a secure website with a questionnaire and an Internet-based audiometry test. Associations, expressed as prevalence ratio (PR), were multivariately modelled using Poisson regression. The questionnaire was answered by 1771 hunters (age 11-91 years), and 202 of them also completed the audiometry test. Subjective severe hearing loss was reported by 195/1771 (11%), while 23/202 (11%) exhibited HFHI upon testing with Internet-based audiometry. As many as 328/1771 (19%) had never used hearing protection during hunting. In the preceding 5 years, 785/1771 (45%), had fired >6 unprotected gunshots with hunting rifle calibers. The adjusted PR of HFHI when reporting 1-6 such shots, relative to 0, was 1.5 [95% confidence interval (CI) 1.1-2.1; P = 0.02]. We could not verify any excessive HFHI prevalence among 89 hunters reporting unprotected exposure to such gunshot noise >6 times. Nor did the total number of reported rifle shots seem to matter. These findings support the notion of a wide variation in individual susceptibility to impulse noise; that significant sound energy, corresponding to unprotected noise from hunting rifle calibers, seems to be required; that susceptible individuals may sustain irreversible damage to the inner ear from just one or a few shots; and that use of hearing protection should be encouraged from the first shot with such weapons.

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.

[Subclinical sensorineural hearing loss in female patients with rheumatoid arthritis]. / Hipoacusia neurosensorial subclínica en pacientes femeninas con artritis reumatoide.

BACKGROUND: The rheumatoid arthritis is a clinical entity capable to cause hearing impairment that can be diagnosed promptly with high frequencies audiometry. OBJECTIVE: To detect subclinical sensorineural hearing loss in patients with rheumatoid arthritis. MATERIAL AND METHODS: Cross-sectional study on patients with rheumatoid arthritis performing high frequency audiometry 125Hz to 16,000Hz and tympanometry. The results were correlated with markers of disease activity and response to therapy. RESULTS: High frequency audiometry was performed in 117 female patients aged from 19 to 65 years. Sensorineural hearing loss was observed at a sensitivity of pure tones from 125 to 8,000 Hz in 43.59%, a tone threshold of 10,000 to 16,000Hz in 94.02% patients in the right ear and in 95.73% in the left ear. Hearing was normal in 8 (6.84%) patients. Hearing loss was observed in 109 (93.16%), and was asymmetric in 36 (30.77%), symmetric in 73 (62.37%), bilateral in 107 (91.45%), unilateral in 2 (1.71%), and no conduction and/or mixed hearing loss was encountered. Eight (6.83%) patients presented vertigo, 24 (20.51%) tinnitus. Tympanogram type A presented in 88.90% in the right ear and 91.46% in the left ear, with 5.98 to 10.25% type As. Stapedius reflex was present in 75.3 to 85.2%. Speech discrimination in the left ear was significantly different (p = 0.02)in the group older than 50 years. No association was found regarding markers of disease activity, but there was an association with the onset of rheumatoid arthritis disease. CONCLUSIONS: Patients with rheumatoid arthritis had a high prevalence of sensorineural hearing loss for high and very high frequencies.

Reduction in high-frequency hearing loss following technical modifications to microvascular decompression for hemifacial spasm.

OBJECT: Microvascular decompression is a safe and effective procedure to treat hemifacial spasm, but the operation poses some risk to the patient's hearing. While severe sensorineural hearing loss across all frequencies occurs at a low rate in experienced hands, a recent study suggests that as many as one-half of patients who undergo this procedure may experience ipsilateral high-frequency hearing loss (HFHL), and as many as one-quarter may experience contralateral HFHL. While it has been suggested that drill-related noise may account for this finding, this study was designed to examine the effect of a number of techniques designed to protect the vestibulocochlear nerve from operative manipulation on the incidence of HFHL. METHODS: Pure-tone audiometry was performed both preoperatively and postoperatively on 67 patients who underwent microvascular decompression for hemifacial spasm during the study period. A change of greater than 10 dB at either 4 kHz or 8 kHz was considered to be HFHL. Additionally, the authors analyzed intraoperative brainstem auditory evoked potentials from this patient cohort. RESULTS: The incidence of ipsilateral HFHL in this cohort was 7.4%, while the incidence of contralateral HFHL was 4.5%. One patient (1.5%; also included in the HFHL group) experienced an ipsilateral nonserviceable hearing loss. CONCLUSIONS: The reduced incidence of HFHL in this study suggests that technical modifications including performing the procedure without the use of fixed retraction may greatly reduce, but not eliminate, the occurrence of HFHL following microvascular decompression for hemifacial spasm.

Etiological classification of presbycusis in Turkish population according to audiogram configuration.

OBJECTIVES: This study aims to classify age related hearing loss in Turkish population according to Schuknecht audiometric configurations for presbycusis and investigate the most common etiologies. PATIENTS AND METHODS: A total of 1,134 patients (568 males, 566 females; mean age 70.5±7.7 years; range 55 to 80 years) with age related hearing loss were included in the study. Audiograms of patients were classified into three categories: high frequency steeply sloping (HFSS), flat, and high frequency gently sloping (HFGS). Speech discrimination scores were evaluated and compared. RESULTS: In the study population, HFSS audiogram configuration was the most frequently observed (48.5%), followed by HFGS configuration (26.9%), and flat configuration (24.5%), respectively. While HFSS audiogram configuration was statistically significantly more common in males, flat audiogram configuration was statistically significantly more common in females (p=0.0001). HFSS group mean air conduction threshold were statistically significantly higher than flat and HFGS groups (p=0.0001). No statistically significantly difference was detected in terms of speech discrimination scores between three groups (p=0.796). CONCLUSION: Results of this study suggest that, in Turkish population, while sensory presbycusis is more common in males, strial presbycusis is more common in females. No difference was detected in terms of the prevalence of cochlear presbycusis in males and females (p=0.0001).

Comparison of two dose-response relationship of noise exposure evaluation results with high frequency hearing loss.

BACKGROUND: Complex noise and its relation to hearing loss are difficult to measure and evaluate. In complex noise measurement, individual exposure results may not accurately represent lifetime noise exposure. Thus, the mean L Aeq,8 h values of individuals in the same workgroup were also used to represent L Aeq,8 h in our study. Our study aimed to explore whether the mean exposure levels of workers in the same workgroup represented real noise exposure better than individual exposure levels did. METHODS: A cross-sectional study was conducted to establish a model for cumulative noise exposure (CNE) and hearing loss in 205 occupational noise-exposed workers who were recruited from two large automobile manufacturers in China. We used a personal noise dosimeter and a questionnaire to determine the workers' occupational noise exposure levels and exposure times, respectively. A qualified audiologist used standardized audiometric procedures to assess hearing acuity after at least 16 h of noise avoidance. RESULTS: We observed that 88.3% of workers were exposed to more than 85 dB(A) of occupational noise (mean: 89.3 ± 4.2 dB(A)). The personal CNE (CNEp) and workgroup CNE (CNEg) were 100.5 ± 4.7 dB(A) and 100.5 ± 2.9 dB(A), respectively. In the binary logistic regression analysis, we established a regression model with high-frequency hearing loss as the dependent variable and CNE as the independent variable. The Wald value was 5.014 with CNEp as the independent variable and 8.653 with CNEg as the independent variable. Furthermore, we found that the figure for CNEg was more similar to the stationary noise reference than CNEp was. The CNEg model was better than the CNEp model. In this circumstance, we can measure some subjects instead of the whole workgroup and save manpower. CONCLUSIONS: In a complex noise environment, the measurements of average noise exposure level of the workgroup can improve the accuracy and save manpower.

Hearing disorders in Turner's syndrome: a survey from Iran.

Turner syndrome (TS) is one of the most frequently encountered sex-linked chromosomal abnormalities, occurring in one per 2,000 female births. These patients present with short stature and failure to begin puberty. In this syndrome, there are multiple organ abnormalities, including auditory disorders. TS patients were referred to the ENT clinic by a pediatric endocrinologist. A questionnaire was filled out and the patients went through a complete otologic examination. They were then referred to the audiology clinic to undergo audiologic test battery plus high-frequency pure tone audiometry. From a total of 48 ears examined, 11 (22.9 %) had a normal audiometry. Mid-frequency sensorineural hearing loss (SNHL), high-frequency SNHL, combined and mixed hearing loss were diagnosed in 6 (12/5 %), 20 (41/7 %), 6 (12/5 %) and 1 (2/1 %) ear, respectively. Tympanogram results showed normal compliance (A, As, Ad) in the majority of cases. B and C patterns were found in a few cases. Speech discrimination score was normal in all patients whereas speech reception threshold was normal in 92 % of the ears. Audiometry abnormality especially SNHL is common in TS patients, with the high-frequency pattern being the most frequent.