Factors affecting high-frequency hearing loss among noise-exposed workers in an automobile manufacturing company / 环境与职业医学

Background The influencing factors of noise hazards in the automotive manufacturing industry are complex, diverse, and mutually correlated, resulting in significant health impacts on workers. Objective To explore the application of generalized estimating equations (GEE) to analyze the factors affecting high-frequency hearing loss among noise-exposed workers in an automotive manufacturing company, guiding enterprises to scientifically carry out employee hearing protection programs. Methods The data of occupational health field evaluation and occupational health surveillance of an automobile manufacturing company for five consecutive years from 2018 to 2022 were collected, and 806 noise-exposed workers with pure tone hearing test results for all five consecutive years were selected as study participants. The retrieved indicators were gender, physical examination year, noise intensity, blood pressure, white blood cell counts, red blood cell counts, platelet counts, concentrations of hemoglobin, alanine transaminase, aspartate aminotransferase, smoking, drinking, etc. Gender, noise intensity, blood pressure, white blood cell counts, red blood cell counts, concentrations of hemoglobin, platelet counts, glutamate aminotransferase, glutamate aminotransferase, smoking, and drinking were set as independent variables, and occurrence of high-frequency hearing loss was set as a dependent variable, and GEE were constructed by using the statistical software of SPSS 20.0 to analyze the influencing factors of high-frequency hearing loss. Results Of the 806 workers, 698 were male (86.6%) and 108 were female (13.4%). The detection rates of high-frequency hearing loss in each year from 2018 to 2022 were 66.4% (535/806), 69.8% (563/806), 70.0% (564/806), 68.9% (555/806), and 68.2% (550/806), respectively. The detection rate of high-frequency hearing loss in the company was varied significantly by gender, lowered white blood cell counts, lowered red blood cell counts, lowered platelet counts, smoking, and drinking (P<0.05). The results of GEE analysis showed that after adjusting for selected confounding factors and excluding interaction effects, the risk of high-frequency hearing loss was higher in men than in women (P=0.001; OR=1.907, 95%CI: 1.286, 2.829); it was higher in workplace with disqualified noise intensity than in those without (P=0.043; OR=1.289, 95%CI: 1.009, 1.648); it was also higher in smokers than in non-smokers (P=0.004; OR=1.507, 95%CI: 1.137, 1.999). Conclusion Gender, noise intensity, and smoking are the main influencing factors of high-frequency hearing loss in noise-exposed workers in this automobile manufacturing company. Controlling smoking and reducing noise exposure intensity may reduce the occurrence of high-frequency hearing loss in workers.

Establishment of a nomogram for predicting the high frequency hearing loss of workers exposed to noise / 中华劳动卫生职业病杂志

Objective@#To explore the related influencing factors of high frequency hearing loss (HFHL) in workers exposed to noise and establish a prediction nomogram for HFHL.@*Methods@#A total of 822 workers exposed to noise from 46 enterprises were included. A questionnaire survey and a pure-tone hearing test were conducted for the workers. The data of noise level of the workers exposed was also collected. After single factor analysis of related influencing factors, the multivariate Logistic regression analysis was performed to identify the final independent influencing factors of HFHL. Finally, a nomogram model was established by R software to achieve individual prediction of HFHL.@*Results@#Among the 822 workers exposed to noise, 166 (20.2%) workers had HFHL. In multivariate Logistic regression analysis, increasing age, men, increasing wearing earphone time, less wearing earplugs, and high noise level were the independent risk factors for HFHL. The C-index of the nomogram model for predicting HFHL was 0.834 (95%CI: 0.748~0.903) . The area under the predictive power curve of nomogram model was 0.834 (95%CI: 0.799~0.869, P<0.001) .@*Conclusion@#Age, sex, wearing earphone time, wearing earplugs, and noise level are independent influence factors for HFHL. The nomogram model is successfully established as a accurate and visible tool for individually predicting the HFHL risk in workers exposed to noise.

Early Experience of Non-Linear Frequency Compression Technology in Patients with High-Frequency Hearing Loss / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Consonants are uttered in the high frequency range in speech to bring out understanding of our language. As consonants convey most of the word information, listeners with high-frequency hearing loss find it hard to understand speech. Non-linear frequency compression (NLFC) technology compresses and moves higher frequencies into a lower frequency region where better residual hearing is present. The purpose of this study was to evaluate clinical effectiveness of NLFC technology in patients with high-frequency hearing loss. SUBJECTS AND METHOD: Twelve ears representing patients with sloping, high-frequency sensorineural hearing loss were involved in this study. Pure-tone audiometry and Threshold Equalizing Noise Test were conducted initially in all subjects. The subjects were tested in the counter-balanced order, and had two months of everyday experience with NLFC on/off before testing took place. A resting period intervened the two phases. Performance was repeatedly evaluated with Sound Field Audiometry, Word Recognition Score, Reception Threshold for Sentences and Korean version of International Outcome Inventory for Hearing Aids. RESULTS: Cochlear dead region was detected on 4 kHz of both ears in only one subject. Each subject showed diverse performance and satisfaction with active NLFC condition. Typically, audibility of high-frequency pure-tones improved with NLFC-on condition. However, speech perception both in quiet and noise was not much improved when compared with NLFC-off condition. CONCLUSION: The NLFC technology could improve audibility in high-frequency, but failed to demonstrate benefits regarding speech perception. Further research is needed to validate the effectiveness of the NLFC technology especially in terms of speech intelligibility.

The Effect of High Frequency Sensorineural Hearing Loss on Auditory Temporal Resolution: Gaps-In-Noise Test Performance in Older and Young Adults with Normal Hearing / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Auditory temporal resolution, which refers to the time-related aspects of acoustic processing, can be evaluated by the Gaps-In-Noise (GIN) test. We investigated whether the presence of high frequency sensorineural hearing loss (HF-SNHL) affects the temporal resolution of GIN performance in older adults with normal hearing. SUBJECTS AND METHOD: Hearing tests including the GIN test were performed in 87 subjects with normal pure tone average. The GIN threshold and percentage of correct answers were compared among 4 groups of participants; older adults with normal hearing (n=18), older adults with HF-SNHL (n=24), young adults with normal hearing (n=24) and young adults with HF-SNHL (n=21). RESULTS: There was no significant difference in the mean GIN thresholds between the HF-SNHL group (5.8+/-0.8 msec) and the normal hearing group (6.0+/-0.8 msec) in older adults, whereas the mean GIN thresholds of HF-SNHL group was higher than that of the normal group in young adults (4.6+/-0.3 msec vs. 4.2+/-0.5 msec, p<0.05). The mean percentage of correct answers of HF-SNHL group (62.5+/-5.5%) was not significantly different from that of the normal hearing group (60.6+/-3.9%) in the old, unlike in the young (71.3+/-4.0% with HF-SNHL vs. 76.9+/-4.3% with normal hearing, p<0.05). Age only showed a significant correlation with the GIN performance. Neither the GIN threshold nor the GIN perception level had any relation with the presence of HF-SNHL in older adults. CONCLUSION: We found no evidence that supported the influence of HF-SNHL on auditory temporal resolution in older adults. These results imply that HF-SNHL may be of little importance in gap detection after age-related changes in central auditory system.

A study on dose -response relationship between human hearing loss and non -stationary noise among workers / 预防医学

Objective To investigate the incidence and risk factors of hearing loss among the workers exposed to non -stationary noise.Methods A cross -sectional study was conducted among the participants.571 male workers without any history of ear disorder were enrolled in this study.They had been exposed to non -stationary noise for one year or more. The history of noise exposure,smoking and drinking behavior were interviewed by using a questionnaire.The noise exposure in the workplace was measured at eight -hour equivalent noise level (LEX.8h )and the thresholds of hearing at 500,1 000,2 000,3 000,4 000 and 6 000 Hz were detected.Results The prevalence of high -frequency hearing loss of two ears was 52.54%,while the prevalence of hearing loss of one ear was 71.98%.There were significant differences of prevalence among different groups of workers in LEX.8h ,duration of noise exposure and the cumulative noise exposure (CNE)(P <0.01).There was a dose response relationship between noise exposure and the risk of hearing loss (P <0.01).Conclusion Non -stationary noise exposure may contribute to hearing loss of workers.There is a good dose -effect relationship between the hearing loss and non -stationary noise.

Audiological manifestations in HIV-positive adults

OBJECTIVE: To characterize the findings of behavioral hearing assessment in HIV-positive individuals who received and did not receive antiretroviral treatment. METHODS: This research was a cross-sectional study. The participants were 45 HIV-positive individuals (18 not exposed and 27 exposed to antiretroviral treatment) and 30 control-group individuals. All subjects completed an audiological evaluation through pure-tone audiometry, speech audiometry, and high-frequency audiometry. RESULTS: The hearing thresholds obtained by pure-tone audiometry were different between groups. The group that had received antiretroviral treatment had higher thresholds for the frequencies ranging from 250 to 3000 Hz compared with the control group and the group not exposed to treatment. In the range of frequencies from 4000 through 8000 Hz, the HIV-positive groups presented with higher thresholds than did the control group. The hearing thresholds determined by high-frequency audiometry were different between groups, with higher thresholds in the HIV-positive groups. CONCLUSION: HIV-positive individuals presented poorer results in pure-tone and high-frequency audiometry, suggesting impairment of the peripheral auditory pathway. Individuals who received antiretroviral treatment presented poorer results on both tests compared with individuals not exposed to antiretroviral treatment. .

The Analysis of High Frequency Sensorineural Hearing Loss Caused by Piston Technique of Stapes Surgery in Patient with Otosclerosis / 听力学及言语疾病杂志

Objective To examine the causes of high frequency sensorineural hearing loss caused by piston technique of stapes surgery.Methods The retrospective analysis involved in thirty cases(49 ears)with stapedectomy from February 2004 to 2009 at our hospital.Pure tone audiometry was performed for each patient who underwent stapedectomy both during the two days preoperation and 1,3,6 months postoperation.Results One month after operation at 8000 Hz,the air conduction hearing threshold was 8 dB less than that before,4 000 Hz average bone conduction hearing threshold was 10 dB less than that before(P < 0.01).The average high-frequency hearingthreshold of ≥40 years old group was noticeably declined than that of 40 years old group(P < 0.01).There was no association between the tinnitus and high frequency hearing loss.(P >0.05).Conclusion Transient high-frequency sensorineural hearing losses occurred to most patients under going stapedectomy,but showed significant improvement,3 months after the surgery.The average high-frequency hearing threshold of ≥40 years old group was seriously declined than that of 40 years old group.

Acoustic analyses of monosyllabic words which are difficult to discriminate in the high frequency hearing loss / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Speech discrimination testing has been used to evaluate the communication disability, select hearing aid candidacy and appropriate amplification, plan and evaluate aural rehabilitation programs and assist in the determination of the site of lesion. Since the words of speech discrimination tests were made on the basis of the linguistic aspects and used till now, they underestimate the disability of high frequency hearing loss (HFHL). To ameliorate this problem, we analysed the words which were difficult to discriminate in FHL in a commonly used speech testing material using the acoustic analysis method. Also, the words were assorted to establish a basic data for a new speech material which could estimate the disability of HFHL. METHODS: 20 HFHL subjects (age 20-70), selected on the basis of pure tone audiometry, were found to be the descending type. They were tested to repeat the monosyllabic words at 10-15dB HL above the puretone threshold of 1000Hz and checked with the error responses. These words were sorted out according to the error response or the confusion rate and analyzed by consonants and vowels. The words were recorded with an audiologist's voice using a GSI 10 audiometer connected to the personal computer. This was analyzed by the acoustic analysis program that has the MATLAB function. With this program, a word was analyzed by an initial consonant, a vowel, and a final consonant for the intensity, the formant peak frequency and the time course. RESULTS: The words which were difficult to discriminate for HFHL were sorted out by the confusion rates. The words of articulation score 15-50% were revealed to have low intensity with short duration, and the peak frequency spectrum above 3 kHz. Also the consonant-vowel transition frequency was located above 3 kHz. CONCLUSION: These results could be used as a basic clinical data to make a new speech discrimination material which evaluates the disability of HFHL more accurately.