[Analysis on the quality control of suspected occupational disease from the characteristics of applicants diagnosed with noise deafness].

Objective: To analyze the audiology and occupational health data of applicants diagnosed of occupational noise deafness, and to explore the influencing factors in the diagnosis of suspected occupational noise deafness. Methods: In May 2022, the information of patients diagnosed with occupational noise deafness in Peking University Third Hospital from January 2018 to December 2021 was collected, and the occupational health data of their working environment, clinical audiological examination results and diagnosis basis of occupational noise deafness were collected and analyzed. Multi-factor unconditional logistic regression analysis was used to analyze independent risk factors for the diagnosis of occupational noise deafness. Results: A total of 129 subjects were included, all of which were suspected cases of occupational noise deafness found in various occupational health examination institutions. Eight cases (6.20%) were diagnosed as occupational noise deafness, and 121 cases (93.80%) were non-occupational noise deafness. After hearing examination, only 27.27% (24/88) of the patients' audiological changes were consistent with the starting point of occupational noise deafness diagnosis. Further analysis of the noise intensity in the workplace showed that 16 patients were identified as non-occupational noise deafness because the noise intensity of the working environment was less than 85 dB. Logistic regression analysis showed that the working hours were more than 8 hours (OR=9.274, 95%CI: 1.388-61.950, P=0.022) and the noise intensity of the working environment (OR=1.189, 95%CI: 1.059-1.334, P=0.003) were independent risk factors for the diagnosis of occupational noise deafness. Conclusion: The exclusion rate of suspected occupational noise deafness found in occupational health examination is higher after adequate rest. The test results of working environment noise intensity provided by the employer can help to determine occupational noise deafness.

Middle Ear Muscle Reflex in Normal-Hearing Individuals with Occupational Noise Exposure.

Objectives: Noise-induced cochlear synaptopathy is studied extensively in animal models. The diagnosis of synaptopathy in humans is challenging and the roles of many noninvasive measures in identifying synaptopathy are being explored. The acoustic middle ear muscle reflex (MEMR) can be considered as a vital tool since noise exposure affects the low-spontaneous rate fibers that play an important role in elicitation of MEMR. The present study aimed at measuring MEMR threshold and MEMR strength. Design: The study participants were divided into two groups. All the participants had normal-hearing thresholds. The control group consisted of 25 individuals with no occupational noise exposure whereas noise exposure group had 25 individuals who were exposed to occupational noise of 85 dBA for a minimum period of 1 year. MEMR threshold and strength was assessed for pure tones (500 Hz and 1000 Hz) and broadband noise. Results: The results showed that the MEMR threshold was similar in both the groups. MEMR strength was reduced in noise exposure group compared to control group. Conclusions: The results of the study suggest that MEMR strength could be used as a sensitive measure in identifying cochlear synaptopathy with careful consideration of the stimulus characteristics.

The relationship between hearing status, listening effort, and the need for recovery in employees of a manufacturing company.

OBJECTIVE: Hearing screening can be used to detect hearing loss, but its value for identifying employees with work functioning difficulties is unclear. The objective of this study was to assess the association between the hearing status measured with an occupational hearing-in-noise screening test, Listening Effort (LE), and Need For Recovery (NFR) in employees of a manufacturing company, and to examine whether these associations depend on the perceived noise level at the workplace. METHODS: Employees of coatings and paints manufacturing company were included. Their hearing status was assessed with an occupational hearing-in-noise screening test. An online survey was used to assess their LE, NFR, and the perceived noise level at the workplace. Responses from 143 employees were analyzed (mean age = 53 years) using hierarchical multiple regression analysis with the outcomes LE and NFR. RESULTS: Regression analysis-with adjustments for gender, age, educational level, health status, pace/amount of work, job variety, and work pleasure-revealed that hearing status was significantly associated with LE, but the interaction between hearing status and the perceived noise level was not. Hearing status nor the interaction between hearing status and the perceived noise level was significantly associated with NFR. CONCLUSION: The results confirm that poorer hearing is associated with higher LE, but not with higher NFR. These associations were unrelated to the perceived noise level at the workplace. Therefore, the value of occupational hearing screening appears to be early identification of hearing loss in employees, but not identification of work functioning difficulties.

Simplified cochlear frequency selectivity measure for sensorineural hearing loss screening: comparison with digit triplet test (DTT) and shortened speech, spatial and qualities of hearing scale (SSQ) questionnaire.

PURPOSE: Pure-tone audiometry (PTA) is the gold standard for screening and diagnosis of hearing loss but is not always accessible. This study evaluated a simplified cochlear frequency selectivity (FS) measure as an alternative option to screen for early frequency-specific sensorineural hearing loss (SNHL). METHODS: FS measures at 1 and 4 kHz center frequencies were obtained using a custom-made software in normal-hearing (NH), slight SNHL and mild-to-moderate SNHL subjects. For comparison, subjects were also assessed with the Malay Digit Triplet Test (DTT) and the shortened Malay Speech, Spatial and Qualities of Hearing Scale (SSQ) questionnaire. RESULTS: Compared to DTT and SSQ, the FS measure at 4 kHz was able to distinguish NH from slight and mild-to-moderate SNHL subjects, and was strongly correlated with their thresholds in quiet determined separately in 1-dB step sizes at the similar test frequency. Further analysis with receiver operating characteristic (ROC) curves indicated area under the curve (AUC) of 0.77 and 0.83 for the FS measure at 4 kHz when PTA thresholds of NH subjects were taken as ≤ 15 dB HL and ≤ 20 dB HL, respectively. At the optimal FS cut-off point for 4 kHz, the FS measure had 77.8% sensitivity and 86.7% specificity to detect 20 dB HL hearing loss. CONCLUSION: FS measure was superior to DTT and SSQ questionnaire in detecting early frequency-specific threshold shifts in SNHL subjects, particularly at 4 kHz. This method could be used for screening subjects at risk of noise-induced hearing loss.

Noise-induced hearing loss profile among Taiwan Airforce on duty pilots.

PURPOSE: Noise-induced hearing loss (NIHL) often results in impaired functional hearing and accidental injuries; thus, reducing military performance and endangering flight safety. While a few studies addressing laterality (left-right ear differences) and NIHL incidence between fixed-winged (jet-fighter) and rotary-wing (helicopter) aircrafts yielded inconsistent results, little is known about the NIHL profile among different types of jet-fighter pilots. This study aims to conduct a fine-grained examination of NIHL among Airforce jet pilots, with planned comparisons of laterality and aircraft type, along with the goal to compare the sensitivity of different hearing indices in predicting military pilot NIHL. MATERIALS AND METHODS: This cross-sectional study utilizes the health and hearing data of 1025 Taiwanese Air Force Military pilots from the 2019 Taiwanese physical examination database to assess the changes in their hearing thresholds, and evaluate their risk for NIHL. RESULTS: Our results showed that, among available military aircraft types, the trainer aircraft and M2000-5 jet-fighter had the highest risk of NIHL, in addition to a left ear inferiority found in the overall population of military pilots. Among the three hearing indices used in this study -the International Organization for Standardization (ISO) three-point hearing index, the Occupational Safety and Health Administration (OSHA) three-point hearing index, and the American Academy of Otolaryngology-Head and Neck Surgery's (AAO-HNS) high-frequency three-point hearing index-, the OSHA the AAO-HNS were the most sensitive. CONCLUSION: Our results suggest a better noise protection for trainer and M2000-5 pilots, especially for the left ear, is warranted.

Using mobile audiometry (Wulira App) to assess noise induced hearing loss among industrial workers in Kampala, Uganda: A cross-sectional study.

BACKGROUND: Occupational noise is a common cause of hearing loss in low-income countries. Unfortunately, screening for hearing loss is rarely done due to technical and logistical challenges associated with pure tone audiometry. Wulira app is a valid and potentially cost-effective alternative to pure tone audiometry in screening for occupational hearing loss. We aimed to determine the prevalence of occupational hearing loss among workers in a metal industry company in Kampala district. METHODOLOGY: We recruited 354 participants conveniently from a steel and iron manufacturing industry in Kampala. All eligible participants answered a pretested and validated questionnaire and were assessed for noise induced hearing loss in a quiet office room approximately 500 meters from the heavy machinery area using the Wulira app. Descriptive statistics such as proportions were used to describe the study population while inferential statistics were used to determine associations. RESULTS: Of the 354 participants sampled, 333 (94.1%) were male, and the median age was 27, IQR (25-30). Regarding the risk factors of hearing loss, fourteen (3.9%) had history of smoking and more than half (65.5%) had worked in the industry for more than 2 years. The overall prevalence of hearing loss among industrial workers was 11.3% (40/354). 16.2% and 9% had mild hearing loss in the right and left ear respectively. Bilateral audiometric notch was present where fourteen (4%) of the participants had notch in their right ear while seven (2%) had notch in their left ear. Residing outside Kampala district was associated with hearing loss (OR, 95% CI, 0.213 (0.063-0.725), p = 0.013). CONCLUSION: One in 10 workers in a metal manufacturing industry in Kampala had occupational hearing loss. Industrial workers residing outside Kampala were likely to develop hearing loss. Periodic screening should be done for early detection and intervention to prevent progression of hearing loss in this population.

Hearing loss and hypertension among noise-exposed workers: a pilot study based on baseline data.

This study aimed to assess the prevalence of noise-induced hearing loss (NIHL) and hypertension, and the association between NIHL and hypertension using occupational physical examination data of 42,588 noise-exposed workers from local enterprises in Yangzhou between 2015 and 2017. The average binaural high-frequency threshold on average (BHFTA), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were 23.09 ± 11.32 dB, 126.85 ± 15.94 mm Hg and 79.94 ± 11.61 mm Hg. The prevalence of NIHL and hypertension were 24.38% and 25.40%. An increased risk of NIHL and hypertension was observed in the groups of males, aged >35 years, noise exposure time >5 years, noise exposure level >85 dB(A) and smoking. 32.25% NIHL workers had hypertension. NIHL workers were at higher risk of hypertension (adjusted OR = 1.07, 95%CI = 1.02-1.13). This study shows that the noise-exposed workers have high risk of developing NIHL and hypertension.

Extended high-frequency audiometry: hearing thresholds in adults.

PURPOSE: This study aimed to determine hearing thresholds in an otologically normal population without occupational noise exposure aged 18 to 64 years using extended high-frequency audiometry (EHFA). METHODS: Individuals from the general population who have never had hearing problems and whose job was not associated with noise exposure were included in the study and classified by age into 5 categories: 18-24 and, further, by 10 years of age. Each of these groups was further divided according to gender. All subjects underwent tympanometry, conventional pure-tone audiometry within the 0.125-8 kHz range, and extended high-frequency audiometry within the 9-16 kHz range, performed according to the standards. The significance level for statistical testing was set at 5%. RESULTS: Here, we established hearing thresholds in an otologically healthy population within the extended high-frequency (EHF) range (9-16 kHz). We found the EHFA to be a highly sensitive method for early detection of hearing loss, with hearing thresholds decreasing as soon as 35 years of age. In males, the hearing thresholds grew with age more rapidly than in women. The ability to respond at EHF gradually decreased with age and increasing frequency. CONCLUSION: Our results can help improve the knowledge of EHF hearing thresholds for individual sexes and age groups. So far, the standard 7029:2017 is not binding and, moreover, it only reaches up to the frequency of 12.5 kHz. EHFA is a highly sensitive method for the evaluation of hearing loss depending on age and sex.

Development of an audiological assessment and diagnostic model for high occupational noise exposure.

PURPOSE: To explore the diagnostic auditory indicators of high noise exposure and combine them into a diagnostic model of high noise exposure and possible development of hidden hearing loss (HHL). METHODS: We recruited 101 young adult subjects and divided them according to noise exposure history into high-risk and low-risk groups. All subjects completed demographic characteristic collection (including age, noise exposure, self-reported hearing status, and headset use) and related hearing examination. RESULTS: The 8 kHz (P = 0.039) and 10 kHz (P = 0.005) distortion product otoacoustic emission amplitudes (DPOAE) (DPs) in the high-risk group were lower than those in the low-risk group. The amplitudes of the summating potential (SP) (P = 0.017) and action potential (AP) (P = 0.012) of the electrocochleography (ECochG) in the high-risk group were smaller than those in the low-risk group. The auditory brainstem response (ABR) wave III amplitude in the high-risk group was higher than that in the low-risk group. When SNR = - 7.5 dB (P = 0.030) and - 5 dB (P = 0.000), the high-risk group had a lower speech discrimination score than that of the low-risk group. The 10 kHz DPOAE DP, ABR wave III amplitude and speech discrimination score under noise with SNR = - 5 dB were combined to construct a combination diagnostic indicator. The area under the ROC curve was 0.804 (95% CI 0.713-0.876), the sensitivity was 80.39%, and the specificity was 68.00%. CONCLUSIONS: We expect that high noise exposure can be detected early with this combined diagnostic indicator to prevent HHL or sensorineural hearing loss (SNHL). TRIAL REGISTRATION NUMBER/DATE OF REGISTRATION: ChiCTR2200057989, 2022/3/25.

The effect of cumulative noise exposure on distortion product otoacoustic emissions.

OBJECTIVE: This study aimed to identify the characteristics of distortion product otoacoustic emissions (DPOAEs) that can be used to differentiate noise-induced hearing loss (NIHL) from age-related hearing loss. A potential index to detect NIHL was defined in terms of its susceptibility to cumulative noise exposure but not to age. DESIGN: In this cross-sectional cohort study, a job-exposure matrix was used to calculate the cumulative noise exposure. Multivariate linear regression models were used to examine how age and cumulative noise exposure associated with DPOAEs at individual frequencies after adjusting for hypertension, dyslipidaemia, tobacco use and alcohol consumption. STUDY SAMPLE: The pure-tone audiometry and DPOAEs data collected from 239 male workers in a steel factory. RESULTS: DPOAEs and DPOAE signal-to-noise ratios (SNRs) at all frequencies were found to be correlated with age, and those at 2, 3, 4 and 6 kHz were correlated with both age and noise exposure. The difference between DPOAE SNR at 1 and 3 kHz showed significant correlation with noise exposure but not with age. CONCLUSIONS: The results showed that this DPOAE index, the DPOAE SNR at 1 kHz minus the DPOAE SNR at 3 kHz, could add values to audiometric evaluation of NIHL.

Acceptability of the Wulira app in assessing occupational hearing loss among workers in a steel and iron manufacturing industry.

BACKGROUND: Industrial workers are at a high risk of acquiring noise induced hearing loss, yet there is minimal hearing loss screening of such groups of people. Pure Tone Audiometry (PTA), the gold standard for hearing loss screening, is expensive, and not readily available at health sites. Mobile audiometry can bridge this gap. However, there is limited knowledge on its acceptability in low-income countries like Uganda. We aimed to assess the acceptability of using the Wulira App, a validated mobile phone app, in assessing hearing loss among industrial workers in Kampala. METHODS: We carried out a qualitative study in a steel and iron manufacturing industry in Kampala, in April 2021. Four Focus group discussions (FGDs) with 8 participants per FGD, and 12 In-depth Interviews (IDI), were conducted on the industrial workers. The industrial workers were first tested for hearing loss, then enrolled for the FGDs and IDI. A semi-structured interview guide was used. Audio recordings were transcribed verbatim. Themes were derived using thematic content analysis, borrowing from Sekhon's model of Acceptability of Health Interventions. RESULTS: Industrial workers found the Wulira App user friendly, cheap, time saving, and an effective hearing loss assessment tool. However, barriers such as lack of smart phones, difficulty in navigating the app, and fear of getting bad news hindered the App's acceptability, as a hearing assessment tool. CONCLUSION: Hearing loss assessment using Wulira App was acceptable to the industry workers. There is need of informing industrial workers on the essence of carrying out regular hearing loss screening, such that barriers like fear of getting screened are overcome.

Estimation of Occupational Noise-Induced Hearing Loss Using Kurtosis-Adjusted Noise Exposure Levels.

OBJECTIVES: Studies have shown that in addition to energy, kurtosis plays an important role in the assessment of hearing loss caused by complex noise. The objective of this study was to investigate how to use noise recordings and audiometry collected from workers in industrial environments to find an optimal kurtosis-adjusted algorithm to better evaluate hearing loss caused by both continuous noise and complex noise. DESIGN: In this study, the combined effects of energy and kurtosis on noise-induced hearing loss (NIHL) were investigated using data collected from 2601 Chinese workers exposed to various industrial noises. The cohort was divided into three subgroups based on three kurtosis (ß) levels (K 1 : 3 ≤ ß ≤ 10, K 2 : 10 <ß ≤ 50, and K 3 : ß > 50). Noise-induced permanent threshold shift at test frequencies 3, 4, and 6 kHz (NIPTS 346 ) was used as the indicator of NIHL. Predicted NIPTS 346 was calculated using the ISO 1999 model for each participant, and the actual NIPTS was obtained by correcting for age and sex using non-noise-exposed Chinese workers (n = 1297). A kurtosis-adjusted A-weighted sound pressure level normalized to a nominal 8-hour working day (L Aeq,8h ) was developed based on the kurtosis categorized group data sets using multiple linear regression. Using the NIPTS 346 and the L Aeq.8h metric, a dose-response relationship for three kurtosis groups was constructed, and the combined effect of noise level and kurtosis on NIHL was investigated. RESULTS: An optimal kurtosis-adjusted L Aeq,8h formula with a kurtosis adjustment coefficient of 6.5 was established by using the worker data. The kurtosis-adjusted L Aeq,8h better estimated hearing loss caused by various complex noises. The analysis of the dose-response relationships among the three kurtosis groups showed that the NIPTS of K 2 and K 3 groups was significantly higher than that of K 1 group in the range of 70 dBA ≤ L Aeq,8h < 85 dBA. For 85 dBA ≤ L Aeq,8h ≤ 95 dBA, the NIPTS 346 of the three groups showed an obvious K 3 > K 2 > K 1 . For L Aeq,8h >95 dBA, the NIPTS 346 of the K 2 group tended to be consistent with that of the K 1 group, while the NIPTS 346 of the K 3 group was significantly larger than that of the K 1 and K 2 groups. When L Aeq,8h is below 70 dBA, neither continuous noise nor complex noise produced significant NIPTS 346 . CONCLUSIONS: Because non-Gaussian complex noise is ubiquitous in many industries, the temporal characteristics of noise (i.e., kurtosis) must be taken into account in evaluating occupational NIHL. A kurtosis-adjusted L Aeq,8h with an adjustment coefficient of 6.5 allows a more accurate prediction of high-frequency NIHL. Relying on a single value (i.e., 85 dBA) as a recommended exposure limit does not appear to be sufficient to protect the hearing of workers exposed to complex noise.

Relationship between occupational noise exposure and hypertension: Cross-sectional evidence from real-world.

Background: Occupational noise is one of the most common and prevalent occupational hazards worldwide and may induce adverse auditory and/or non-auditory health effects. However, the relationship between occupational noise exposure and hypertension is controversial and has long been debated. Methods: Based on large sample cross-sectional data from all registered occupational health examination units from 2021 to 2022 (N = 101,605), this study aimed to analyze the prevalence of hearing loss and hypertension and to explore the influencing factors of hypertension of workers in Wuhan. Descriptive statistics, univariate analyses and multivariate analyses were used. Forest plot and nomograms were constructed for the visualization of predictive results. The ROC curve, AUC, C-index and calibration curves were used to assess the predictive accuracy and validity. DCA was performed to evaluate the net benefit that workers could receive. Results: Higher rate of high-frequency hearing loss (25.3%), speech frequency hearing loss (8.8%), ECG abnormalities (31.9%) and hypertension (21.0%) were found in workers exposed to occupational noise in Wuhan. Occupational noise exposure (OR = 1.09, 95% CI: 1.01-1.18, p = 0.04), growth of age (OR: 1.07, 95% CI: 1.07-1.07, p < 0.001), overweight (OR: 1.82, 95% CI: 1.73-1.92, p < 0.001), obesity (OR: 3.62, 95% CI: 3.42-3.83, p < 0.001), hyperglycemia (OR: 1.84, 95% CI: 1.73-1.96, p < 0.001), hypercholesterolemia (OR = 1.34; 95% CI 1.22-1.48; p < 0.001), ECG abnormalities (OR = 1.11; 95% CI 1.07-1.15; p < 0.001) and family history of hypertension (OR = 1.69; 95% CI 1.58-1.81; p < 0.001) were risk factors of hypertension for workers. Male workers had a relatively higher hypertension risk than female workers (OR = 1.61; 95% CI 1.54-1.69; p < 0.001). Ear protective measures could not reduce the risk of hypertension in workers. Our nomogram has good predictive accuracy and validity. A dynamic nomogram to predict the workers' risk of hypertension was established publicly available online. Conclusion: Occupational noise exposure may elevate workers' hypertension risk. More effective and relevant prevention measures should be taken. Our nomogram may help identify high-risk workers and facilitate timely interventions.

Trends in Hearing Protection Use With Occupational Noise Exposure in the United States 1999 to 2016.

OBJECTIVE: Determine hearing protection use in relation to occupational noise exposure, tinnitus, and audiometry-measured hearing loss in the United States from 1999 to 2016. STUDY DESIGN: Cross-sectional study utilizing US National Health and Nutritional Examination Survey (NHANES) 1999 to 2016 with occupation, reported occupational noise exposure, hearing protection use, tinnitus, and audiometry-measured hearing loss data. Subgroup analysis divided data into two cohorts early 2000s and 2010s. SETTING: Population-based study using NHANES database capturing representative sample of US population. PARTICIPANTS: Individuals with complete data 1999 to 2004 (n = 10,347) and 2011 to 2012 with 2015 to 2016 (n = 9,383). INTERVENTIONS: Participants self-reported occupational noise exposure lasting more than 4 h/d for more than 3 months. Self-reported hearing protective device uses and tinnitus frequency. Audiometric hearing loss objectively measured. MAIN OUTCOME MEASURES: Hearing protection use. Secondary measures included self-reported bothersome tinnitus and audiometrically measured hearing loss. RESULTS: Across occupations, reported occupational noise exposure was higher in 2010s [32%, 95% CI: 29.6-34.6%] than 2000s [12.5%, 95% CI: 11.2-13.9%], while hearing protection use remained low in 2000s [41.3%, 95% CI: 37.8-44.8%] and 2010s [32.8%, 95% CI: 29.8-35.8%]. Less hearing protection use was associated with absence of bothersome tinnitus. Factors associated with increased hearing protection use were younger age, male sex, college education or higher, and white race in a multivariate model. CONCLUSIONS: Reported occupational noise exposure appeared to increase from 2000s to 2010s yet hearing protection use remained stable at low use rate. As noise exposure is a major risk factor for hearing loss, significant education and reinforcement of appropriate hearing protection use for workplace noise exposures is necessary to preserve workers' hearing.

Corrigendum: Occupational noise and age: A longitudinal study of hearing sensitivity as a function of noise exposure and age in South African gold mine workers.

No abstract available.

Tinnitus characteristics at high-and low-risk occupations from occupational noise exposure standpoint.

INTRODUCTION: The aim of the present study was to compare tinnitus characteristics in high- and low-risk occupations from the occupational noise exposure standpoint, considering demographic data, hearing loss and concomitant diseases. METHODS: Demographic data, characteristics of tinnitus, hearing and concomitant diseases were recorded in the questionnaires. Their pure tone air conduction thresholds were determined using a double-channel diagnostic Audiometer and the Bone Conduction was assessed using a B-71 bone vibrator. RESULTS: Totally, 6.3% subjects (6.8% high-risk group and 5.6% low-risk group) had subjective tinnitus, mainly as whistling sound. In the high-risk group, tinnitus was mainly left-sided (41.18%) and hearing loss was mild. Bilateral tinnitus (52.63%) and slight hearing loss were observed predominantly in the low-risk group. CONCLUSIONS: The study showed higher incidence of tinnitus in high-risk professions regarding with occupational noise exposure.

Effect and Biocompatibility of a Cross-Linked Hyaluronic Acid and Polylactide-co-glycolide Microcapsule Vehicle in Intratympanic Drug Delivery for Treating Acute Acoustic Trauma.

The treatment of acute hearing loss is clinically challenging due to the low efficacy of drug delivery into the inner ear. Local intratympanic administration of dexamethasone (D) and insulin-like growth factor 1 (IGF1) has been proposed for treatment, but they do not persist in the middle ear because they are typically delivered in fluid form. We developed a dual-vehicle drug delivery system consisting of cross-linked hyaluronic acid and polylactide-co-glycolide microcapsules. The effect and biocompatibility of the dual vehicle in delivering D and IGF1 were evaluated using an animal model of acute acoustic trauma. The dual vehicle persisted 10.9 times longer (8.7 days) in the middle ear compared with the control (standard-of-care vehicle, 0.8 days). The dual vehicle was able to sustain drug release over up to 1 to 2 months when indocyanine green was loaded as the drug. One-third of the animals experienced an inflammatory adverse reaction. However, it was transient with no sequelae, which was validated by micro CT findings, endoscopic examination, and histological assessment. Hearing restoration after acoustic trauma was satisfactory in both groups, which was further supported by comparable numbers of viable hair cells. Overall, the use of a dual vehicle for intratympanic D and IGF1 delivery may maximize the effect of drug delivery to the target organ because the residence time of the vehicle is prolonged.

Association of occupational noise exposure, bilateral hearing loss with hypertension among Chinese workers.

OBJECTIVE: To evaluate the relationship of occupational noise, bilateral hearing loss with blood pressure and hypertension among a Chinese population. METHODS: We included 15 422 individuals from a cross-sectional survey of the key occupational diseases in 2017 in Wuhan, Hubei Province, China. Occupational noise exposure was evaluated through workplace noise level and/or the job titles. Hearing loss was defined as a pure-tone average of 25 dB or higher at speech frequency (0.5, 1, 2 kHz) or high frequency (3, 4, 6 kHz) in both ears. Hypertension was defined as blood pressure at least 140/90 mmHg or self-reported current use of antihypertensive medication. RESULTS: Compared with participants without occupational noise exposure, the prevalence of hypertension was significantly higher for noise exposure duration of 5 to less than 10 years [odds ratio (OR) = 1.13, 95% confidence interval (CI) = 1.04-1.27] and at least 10 years (OR = 1.17, 95% CI = 1.09-1.30). In the sex-specific analysis, the association was significantly pronounced in male (OR = 1.18, 95% CI = 1.06-1.32 for duration of 5 to <10 years; OR = 1.25, 95% CI = 1.12-1.38 for duration ≥10 years), but not in female (OR = 1.01, 95% CI = 0.80-1.11 for duration of 5 to <10 years; OR = 1.06, 95% CI = 0.90-1.20 for duration ≥10 years). In the subsample analyses, bilateral hearing loss was associated with a higher prevalence of hypertension, no matter for speech frequency hearing loss (OR = 1.12, 95% CI = 1.02-1.30 for mild; OR = 1.35, 95% CI = 1.20-1.50 for severe) or for high-frequency hearing loss (OR = 1.24, 95% CI = 1.03-1.50 for mild; OR = 2.40, 95% CI = 1.80-3.17 for severe). The sex-subgroup analysis of hearing loss with hypertension was similar as occupational noise and hypertension. CONCLUSION: Our study has suggested occupational noise exposure is a potential risk factor for hypertension.

Auditory effects of recreational and occupational noise exposure among dental students: a cross-sectional study / Efectos auditivos producto de la exposición a ruido recreacional y dental en estudiantes de odontología: un estudio transversal

ABSTRACT Purpose: to determine the auditory effects of noise exposure from recreational and occupational sources among dentistry students. Methods: forty-two dentistry students, routinely exposed to occupational noise, and 72 students from other health science schools were recruited (control group). Audiometric testing, otoacoustic emissions and questionnaires to assess recreational and occupational noise were applied to the sample. The presence of a notch was determined for each participant audiometry´s test based on the criteria proposed by Coles et al. Differences in notch prevalence were analyzed by applying univariate regression models as well as a multivariate model adjusted by covariates. Results: non-significant differences in auditory thresholds between groups were found. The controls exhibited a significantly higher prevalence of a notch at 4 kHz than the group exposed to noise. However, the differences were not statistically significant in the multivariate model adjusted by recreational noise exposure. Conclusions: the occupational noise exposure was not significantly associated to auditory system dysfunction. In addition, the differences in notch prevalence could be related to recreational noise exposure.

RESUMEN Objetivo: determinar los efectos auditivos producto de la exposición a ruido recreacional y ocupacional en estudiantes de Odontología. Métodos: se reclutó a 42 estudiantes de odontología expuestos rutinariamente a ruido ocupacional, y a 72 estudiantes de otras carreras del área de la salud (grupo control). Se evaluó mediante audiometría, emisiones otoacústicas, junto con aplicar cuestionarios para determinar la exposición a ruido ocupacional y recreacional. A partir de los umbrales audiométricos e determinó la presencia de escotoma usando el criterio de Coles et al. Se analizaron las diferencias en prevalencia de escotomas entre los grupos mediante regresiones logísticas, ajustando por otras variables. Resultados: no existieron diferencias significativas en los umbrales audiométricos entre los grupos estudiados. El grupo control mostró mayor prevalencia de escotoma en 4 kHz al ajustar por sexo y edad, sin embargo, dejó de ser significativa al ajustar adicionalmente por exposición a ruido recreacional. Conclusiones: la exposición a ruido ocupacional no se asoció a alteraciones auditivas. Además, las diferencias en prevalencia de escotomas estarían relacionadas a exposición a ruido recreacional.

Hearing function of gold miners with and without a history of tuberculosis treatment: a retrospective data review / Função auditiva de garimpeiros com e sem história de tratamento de tuberculose: uma revisão retrospectiva dos dados

Abstract Introduction: South Africa has a high prevalence of co-existing tuberculosis and HIV. As ototoxicity linked to the treatments for these conditions occurs with concomitant exposure to other ear toxins such as hazardous noise exposure, it is important to investigate the combination impact of these toxins. Limited published evidence exists on the co-occurrence of these conditions within this population. Objectives: The objective of this study was to compare the hearing function of gold miners with (treatment group) and without (non-treatment group) the history of tuberculosis treatment, in order to determine which group had increased risk of noise induced hearing loss. Furthermore, possible influence of age and HIV in these two groups was examined. Methods: A retrospective record review of 102 miners' audiological records, divided into two groups, was conducted, with data analyzed both qualitatively and quantitatively. Results: Findings suggest that gold miners with a history of tuberculosis treatment have worse hearing thresholds in the high frequencies when compared to those without this history; with evidence of a noise induced hearing loss notch at 6000 Hz in both groups. Pearson's correlations showed values between 0 and 0.3 (0 and −0.3) which are indicative of a weak positive (negative) correlation between HIV and hearing loss, as well as between hearing loss and age in this population. Conclusions: Current findings highlight the importance of strategic hearing conservation programs, including ototoxicity monitoring, and the possible use of oto-protective/chemo-protective agents in this population.

Resumo Introdução: A África do Sul apresenta uma alta prevalência de coinfecção de tuberculose e HIV. Como a ototoxicidade associada aos tratamentos para essas condições é observada na exposição concomitante a outros agentes ototóxicos, como a exposição a ruídos perigosos, é importante investigar o impacto da combinação desses agentes. São poucas as evidências publicadas sobre a co-ocorrência dessas condições nessa população. Objetivo: Comparar a função auditiva de garimpeiros com (grupo tratamento) e sem (grupo sem tratamento) história de tratamento de tuberculose, a fim de determinar que grupo apresentava maior risco de perda auditiva induzida por ruído. Além disso, avaliou-se a possível influência da idade e do HIV nesses dois grupos. Método: Os registros audiológicos de 102 garimpeiros, divididos em dois grupos, foram revisados de forma retrospectiva; os dados foram qualitativa e quantitativamente analisados. Resultados: Os achados indicam os garimpeiros com histórico de tratamento de tuberculose apresentam piores limiares auditivos nas altas frequências quando comparados àqueles sem esse histórico; em ambos os grupos, observou-se perda auditiva induzida por ruído com entalhe audiométrico a 6.000 Hz. As correlações de Pearson mostraram valores entre 0 e 0,3 (0 e -0,3), que são indicativos de uma fraca correlação positiva (negativa) entre o HIV e a perda auditiva, bem como entre a perda auditiva e a idade nessa população. Conclusões: Os resultados atuais destacam a importância de programas estratégicos de conservação auditiva, inclusive monitoramento de ototoxicidade, e o possível uso de agentes oto-/quimioprotetores nessa população.