Salud auditiva y exposición a ruido ambiental en población de 18 a 64 años de Bogotá, Colombia, entre el 2014 y el 2018.

Introducción. La salud auditiva es un tema de interés en salud pública que afecta la calidad de vida y que puede afectarse por la exposición continua al ruido, un factor de riesgo que genera síntomas auditivos y extraauditivos. OBJETIVO: Identificar el estado de salud auditiva de adultos que viven en Bogotá, y su asociación con factores de exposición a ruido ambiental, individuales y otológicos. Materiales y métodos. Se realizó un estudio transversal mediante el análisis de una base de datos con 10.311 registros, obtenidos entre los años 2014 y 2018, producto de una encuesta estructurada de percepción de ruido y tamizaje auditivo. Se hizo un análisis descriptivo bivariado y una regresión logística binaria. RESULTADOS: El 35,4 % de los participantes presentó disminución auditiva. En el componente de percepción: 13,0 % refirió no escuchar bien, 28,8 % informó síntomas extraauditivos, 53,3 % tenía antecedentes otológicos, y 69,0 % manifestó molestia por ruido extramural. En la regresión logística, las variables más asociadas con disminución auditiva fueron: de las ambientales, vivir en zonas de mayor ruido (OR = 1,50) (IC95%: 1,34-1,69); de las individuales, ser hombre (OR = 1,85) (IC95%: 1,64-2,09) y la edad (por cada año de vida, el riesgo de disminución auditiva aumentó 6 %); y de las otológicas, tener antecedente de síntomas otológicos (OR = 1,86) (IC95%: 1,66-2,08). CONCLUSIONES: La disminución auditiva es multicausal en la población evaluada. Los factores que aumentan su prevalencia son incremento de la edad, ser hombre, tabaquismo, medicamentos ototóxicos, vivir en zonas de mayor exposición a ruido y presentar síntomas extraauditivos.

Awareness, attitudes and perceptions of students towards leisure noise in Durban, South Africa.

BACKGROUND:  Young adults are exposed to high noise levels in leisure venues, which increases their risk of hearing loss, and can affect their quality of life. OBJECTIVES:  The aim of this study was to describe the young adults' awareness, attitudes and perceptions towards leisure noise at a university in South Africa. METHOD:  A descriptive cross-sectional study design with quantitative methods of data was considered for this study. Students from first to fourth years in the Education Department of a local university in Durban, South Africa, who were aged 18 years old - 25 years old were invited to participate in an online survey. RESULTS:  Of the 462 participants, most had a general awareness on noise and hearing loss but lacked knowledge on the negative effect of loud noise, with 95.2% using personal listening devices, followed by visiting restaurants and gyms, and 48.3% being unsure if noise can damage hearing permanently. They were unaware of methods to reduce their exposure to noise. A significant relationship between awareness of noise and attitudes (p = 0.029) indicated that the higher the level of awareness regarding leisure noise, the better their attitude and behaviour, thus the lower the risk of hearing loss. CONCLUSION:  The results highlight the need for implementing the World Health Organization (WHO) noise regulations and providing education for this age group to prevent irreversible hearing loss through exposure to leisure noise.Contribution: A national study is recommended to increase research evidence.

Effect of age-related extended high frequency hearing loss on the subjective impressions of dental drill noise.

Fear and anxiety among patients are sometimes evoked in dental clinics due to the sound of dental drills. This study aimed to explore the impact of age-related hearing loss in the extended high frequency (EHF) range above 8 kHz on individuals' subjective discomfort towards dental drill noise. After measuring pure-tone audiometric thresholds at both conventional and extended high frequencies, we used a psychoacoustic approach to evaluate subjective impressions of four dental drill sound stimuli, which featured varying frequency components, in 62 participants (aged 12-67 years). We found a significant decrease in hearing sensitivity within the EHF range as age increased, with notable differences in hearing thresholds at 14 kHz between teenage and older adults exceeding 65 dB. Furthermore, significant differences were observed between younger and older (above 40 years) participants in the subjective impressions of dental drill noise, emphasizing age as a critical factor in the perception of high frequency components. Consequently, age may influence the unpleasantness of dental drilling noise. Compared to older individuals, young participants may exhibit increased fear of dental procedures owing to physiological factors. These results underscore the need for age-appropriate noise control strategies in dental clinics to mitigate anxiety and improve patient comfort.

Oxidative Stress Assessment of Noise Exposure in the Workers Using Hearing Protection in a Pressing Industry.

BACKGROUND AND OBJECTIVE: Exposure to noise by generation of free radicals causes oxidative stress in body. The aim of this study was the evaluation of oxidative stress in workers who have used hearing protection devices during working time. MATERIAL AND METHOD: Pressing workers (n=24) of a home appliance industry were studied using hearing protection devices to reduce noise exposure. Twenty two office staff (without exposure to noise) were considered as a control group. Two groups were matched for age, work experience and smoking. Exposure to noise was measured by dosimeter method at workstations. By obtaining 3 ml blood sample, Malondialdehyde levels, Thiol groups and total antioxidant capacity were evaluated in all subjects. RESULTS: Exposure to sound pressure level in pressing workers by considering the noise reduction factor of the earplug was observed in 77.65 dB with minimum 75.1 dB and Maximum 81.22 dB. Plasma thiol groups (0.076 (0.041-0.119) vs (0.110 (0.076-0.197), mmol/l P =0.0001) and total antioxidant capacity (361.33± 54.65 vs 414.14± 96.82, µmol/ml P = 0.026) in pressing workers significantly decreased than control group. Pearson correlation showed significant results between exposure to noise and oxidative stress parameters. CONCLUSION: Exposure to noise wave cause oxidative stress in different site of body. Oxidative stress is an intermediate way for different disease due to noise exposure. Reducing of noise exposure by earplug in pressing workers is not efficient protection for oxidative stress generation. Therefore, hearing protection devices are not a barrier to the harmful effects of noise in occupational exposure.

A Comprehensive Review of Auditory and Non-Auditory Effects of Noise on Human Health.

OBJECTIVE: Excessive noise is unpleasant and induces several physiological and psychological effects. Noise pollution is a potential threat to humans, particularly those continuously exposed for extended periods throughout the day over many years. This review aims to examine the various auditory and non-auditory outcomes associated with prolonged exposure to noise pollution. MATERIALS AND METHODS: The review utilized a combination of relevant keywords to search the electronic databases. After screening based on the applied selection criteria for title, abstract, and full text, 44 articles were finally selected for critical review. RESULTS: We identified and analyzed research findings related to noise-induced hearing loss, tinnitus, and sleep disturbances along with non-auditory issues such as annoyance, cognitive impairments, and mental stress associated with cardiovascular disorders. Furthermore, the existing studies were compared and collated to highlight the unique challenges and significance of noise pollution as a distinctive environmental concern and to explore the ongoing efforts in its research and prevention, including the early detection and potential reversal of noise-induced hearing loss. CONCLUSION: The fundamental health consequences of noise pollution underscore the need for extensive research encompassing emerging noise sources and technologies to establish a health management system tailored to address noise-related health concerns and reduce noise exposure risk among populations. Finally, further research is warranted to ensure improved measurement of noise exposure and related health outcomes, especially in the context of occupational noise.

Influence of Different Noise Types on Hearing Function in Patients Treated for Mild Otitis Media.

BACKGROUND: Otitis media (OM) refers to a common clinical ear disease. Noise seriously damages human hearing function. This study aimed to investigate the effects of various noise types on the hearing function of patients who have recovered from mild OM. MATERIALS AND METHODS: A total of 160 patients with mild OM treated at our hospital from May 2020 to May 2023 were retrospectively selected for this study. Based on clinical data, the patients were divided into the non-noise group (n = 80) and the noise (n = 80) group. The hearing thresholds of the two groups were compared across various noise types at 500, 1000, and 2000 Hz. In addition, the hearing thresholds of the noise group were compared under the same conditions. RESULTS: The noise group exhibited significantly higher hearing thresholds at 500, 1000, and 2000 Hz than the non-noise group (P < 0.05). Under traffic, urban construction, and industrial noises, the auditory thresholds at 500, 1000, and 2000 Hz in the noise group were significantly higher than those observed under domestic and speech noises (P < 0.05). CONCLUSION: Noise shows a close relationship with the hearing function of patients with OM. Traffic, urban construction, and industrial noises greatly influence the hearing function of patients who have recovered from mild OM.

Cross-sectional study on the health of workers exposed to occupational noise in China.

OBJECTIVE: This study aimed to understand the health of workers exposed to occupational noise and explore the influencing factors related to workers' health, especially the impact of noise on workers' hearing. This work can provide a basis for formulating relevant measures for occupational noise prevention and control in the future. METHODS: On the basis of the key occupational disease monitoring project in Chongqing, China, in 2021, the data of 1125 workers exposed to occupational noise were analyzed. Data included demographic information, occupational history, clinical physical examination information, and noise detection information of the working environment. Chi-square test and multifactorial logistic regression were used for statistical analysis. RESULTS: The prevalence rates of abnormal electrocardiogram (ECG), blood pressure (BP), and pure tone audiometry (PTA) were 21.9% (246/1125), 27.8% (313/1125), and 18.0% (202/1125), respectively. Male workers accounted for 78.8%. Compared with male workers, female workers had a lower prevalence of abnormal PTA (OR = 0.28, 95% CI = 0.16-0.50). Workers working in medium enterprises had a lower prevalence of abnormal BP than workers in micro enterprises (OR = 0.36, 95% CI = 0.19-0.66). The prevalence of abnormal BP and PTA of workers increased with age. After adjusting for age, sex, and body mass index, the prevalence of abnormal ECG of mining workers was higher than that of manufacturing workers (OR = 1.54, 95% CI = 1.07-2.24), and the prevalence of abnormal PTA had a rising trend with the increase in noise exposure value. CONCLUSION: Noise-exposed workers have a high prevalence of abnormal ECG, BP, and PTA, and factors such as age, enterprise size, and workplace noise exposure are correlated with the aberrant health of workers. Governments, enterprises, and individuals need to attach great importance to the possible adverse effects of noise. They must also actively adopt various effective measures to protect the occupational safety and health of workers.

Perfil das doenças metabólicas na perda auditiva ocupacional / Profile of metabolic damages in occupational hearing loss / Perfil de enfermedades metabólicas en la pérdida auditiva ocupacional

Introdução: O diagnóstico precoce quanto às perdas auditivas é essencial para minimização do impacto social em relação à rotina laboral e na qualidade de vida. Objetivo: Caracterizar a associação entre a perda auditiva em trabalhadores com doenças metabólicas. Método: Estudo transversal retrospectivo de dados secundários de prontuário com o tratamento das doenças metabólicas, os dados foram coletados em duas clínicas de saúde ocupacional (C1 e C2) em Florianópolis - Santa Catarina (Brasil), no período de janeiro de 2020 a dezembro de 2022, considerando exames referenciais a partir do ano de 2005. Os dados foram organizados em planilhas do programa Microsoft Excel® e, posteriormente, exportados e analisados no software MedCalc® Statistical Software versão 22.006. Resultados: Foram analisados dados de 97 pacientes (71 homens e 26 mulheres), expostos ao ruído ocupacional (p = 0,0047), com diagnóstico de ao menos uma doença metabólica (41,20%) e prevalência de medicamentos da classe ATC H (p = 0,0465) e Losartana® (OR = 1,6976). Conclusão: O ruído ocupacional é o principal fator de risco auditivo nas empresas analisadas, e a presença de doença metabólica poderá influenciar em alterações dos limiares auditivos. Para reduzir a vulnerabilidade dessa população, é necessário a promoção, educação e conscientização dos trabalhadores nos aspectos de saúde. (AU)

Introduction: Early diagnosis of hearing loss is essential to minimize the social impact in relation to work routine and quality of life. Objective: Analyze the association between hearing loss in workers and metabolic diseases. Method: Retrospective cross-sectional study of secondary data on the use of medications in metabolic diseases, the data were collected in two occupational health clinics (C1 and C2) in Florianópolis - Santa Catarina (Brazil), from January 2020 to December 2022, considering references from exams from the year 2005. The data were organized in Microsoft Excel® spreadsheets and subsequently exported and analyzed using the MedCalc® statistical software version 22.006. Results: The data of 97 patients (71 men and 26 women) exposed to occupational noise (p = 0.0047), diagnosed with at least one metabolic disease (41.20%) and prevalence of ATC H class medications (p = 0.0465) and Losartan® (OR = 1.6976). Discussion andConclusion: Occupational noise is the main auditory risk factor, and the presence of metabolic disease can influence hearing thresholds. To reduce the vulnerability of this population, it is necessary to promote, raise awareness and educate, using approaches related to health aspects at work. (AU)

Introducción: El diagnóstico precoz de la pérdida auditiva es fundamental para minimizar el impacto social en la rutina laboral y la calidad de vida. Propósito: Analizar la asociación entre pérdida auditiva en trabajadores y enfermedades metabólicas. Metodología: Estudio transversal retrospectivo de datos secundarios sobre el uso de medicamentos en enfermedades metabólicas; Los datos fueron recolectados en dos clínicas de salud ocupacional (C1 y C2) en en Florianópolis - Santa Catarina (Brasil), de enero de 2020 a diciembre de 2022, considerando referencias de exámenes del año 2005. Los datos fueron organizados en hojas de cálculo Microsoft Excel®. y posteriormente exportados y analizados. utilizando el software estadístico MedCalc® versión 22.006. Resultados: Se analizaron los datos de 97 pacientes (71 hombres y 26 mujeres) expuestos a ruido ocupacional (p = 0,0047), diagnosticados con al menos una enfermedad metabólica (41,20%) y prevalencia de medicamentos clase ATC H (p = 0,0465). y Losartan® (OR = 1,6976). Discusión y Conclusión: El ruido ocupacional es el principal factor de riesgo auditivo y la presencia de enfermedad metabólica puede influir en los umbrales auditivos. Para reducir la vulnerabilidad de esta población es necesario promover, sensibilizar y educar utilizando enfoques relacionados con aspectos de salud en el trabajo. (AU)

White noise use among children undergoing sound field audiometry: A preliminary study.

OBJECTIVE: To describe the prevalence of routine white noise exposure in children who undergo sound field audiometry. METHODS: A retrospective cohort study was conducted at a pediatric otolaryngology clinic affiliated with an academic tertiary care hospital. The medical records of children who underwent sound field audiometry were reviewed and data was collected regarding demographics and audiogram results. The group was divided into two cohorts based on routine exposure to white noise. Children exposed to white noise were tested with warble tones, while those not exposed were tested with narrow-band noise. RESULTS: 127 patients underwent sound field audiometry testing, of which 96 (75.6%) were reported by their parents to use white noise for sleep. The mean age at time of testing was 1.6 years (95% Confidence Interval [CI] 1.5-1.7). 104 (81.9%) children were able to respond to at least four of the sound field thresholds, and there was no significant difference between the children exposed to white noise and those who were not (P = 0.459). Mean pure tone average (PTA) was 26.2 dB (95% CI 25.2-27.2) and mean speech reception threshold (SRT) was 19.2 dB (95% CI 18.2-20.2). The sound field response rate, PTA, and SRT were similar between these two groups. CONCLUSIONS: The routine use of white noise therapy was extremely common in this pediatric population. The use of warble tones as the audiometric stimuli for children exposed to white noise resulted in similar testing success compared to the use of narrow-band noise in children not exposed to white noise.

[Quantitative analysis of the characteristics and influencing factors of hearing loss among workers exposed to noise in Tianjin].

Objective: To analyze the characteristics of high-frequency average hearing loss in both ears of noise exposed workers in Tianjin in 2020, and quantitatively analyze the influencing factors of high-frequency hearing loss in both ears of workers. Methods: In March 2023, Collect and organize basic information about noise-hazardous enterprises and personal information of workers exposed to noise. Data from the Tianjin Occupational Disease and Health Hazard Factors Information Monitoring System from January 2020 to December 2020, and analyze the impact of basic information of employees, enterprise size, regional distribution, industry category, and economic type on the high-frequency average hearing loss of workers during work. Apply logistic regression to quantitatively analyze the influencing factors of abnormal high-frequency average hearing threshold of noise exposed workers. Results: The size, economic type, industry category, and regional distribution of enterprises, as well as the gender, age, length of service of workers, have an impact on the abnormal high-frequency average hearing threshold of noise exposed workers (χ(2)=733.56、3 497、27、1352.84、1197.62、2570.59、22.30、506.60, P<0.001) . Quantitative analysis using a logistic regression model showed that in the basic information of workers, noise exposed workers were male (OR=2.500, P<0.001) and aged 30-39, 40-49, and 50-59 years (OR=1.33, P<0.001; OR=1.68, P<0.001; OR=1.52, P< 0.001) , with a length of service of 4 to<10 years and≥10 years (OR=1.08, P<0.001; OR=1.615, P<0.001) being the influencing factors for high-frequency hearing loss in both ears of noise exposed workers; In terms of enterprise characteristics, medium-sized, small and micro enterprises (OR=1.12, P<0.001; OR=1.75, P<0.001; OR=2.09, P<0.001) , enterprises located in the fourth district around the city (OR=1.268, P<0.001) , and enterprises with economic types of collective economy, other economy, private economy, Hong Kong, Macao and Taiwan investment, shareholding system, and other industry economies (OR are all >1, P<0.001) are all factors affecting high-frequency hearing loss in noise exposed personnel. Conclusion: Noise is a common occupational hazard factor in Tianjin's enterprises, especially for workers in micro enterprises who face a high risk of hearing abnormalities. Therefore, enterprises need to strengthen the management and intervention of noise operations to prevent the occurrence of hearing loss in workers.

Sources of noise exposure across Australian workplaces: cross-sectional analysis and modelling the impact of a targeted noise-source reduction initiative.

CONTEXT: Workplace noise regulations and guidance follow the hierarchy of control model that prioritizes eliminating or reducing noise at its source. OBJECTIVES: To determine the main sources of workplace noise exposure in the Australian working population and estimate the reduction of workers exposed over the noise limit (LAeq,8h > 85 dB) if noise levels of specific tools or equipment were reduced by 10 dB. METHODS: Information on the tools used and tasks performed during each participant's last working shift was collected from 4,977 workers via telephone survey. Using a predetermined database of task-based noise levels, partial noise exposures (Pa2h) were determined for each noisy activity performed by the workers and their daily noise exposure level (LAeq,8h) was estimated. Partial exposures were categorized into 15 tool/task groups and the tally, average, and sum (Pa2h) for each group were calculated. The impacts of 5 different scenarios that simulated a reduction of 10 dB in noise emissions for specific tool groups were modelled. RESULTS: Powered tools and equipment were responsible for 59.3% of all noise exposure (Pa2h); vehicles for 10.6%; mining, refineries, and plant equipment for 5.1%; and manufacturing and food processing for 4.2%. Modelling demonstrated that a 10 dBA noise-level reduction of all powered tools and equipment would lead to a 26.4% (95% confidence interval: 22.7% to 30.3%) reduction of workers with an LAeq,8h > 85 dB. This could represent over 350,000 Australian workers no longer exposed above the workplace limit daily. CONCLUSIONS: A universal reduction of 10 dB to power tools and equipment would substantially reduce the future burden of hearing loss, tinnitus, workplace injuries, and other health effects. Initiatives to reduce the noise emissions of specific powered tool groups are warranted.

Recreational music exposure and hearing health in young adults.

OBJECTIVE: This study aimed to compare daily and total recreational music exposure levels and extended-spectrum audiogram results in young adults without pre-existing hearing problems. DESIGN: The study included healthy volunteers aged 18-25 with no known ear disease or hearing loss. Participants completed a questionnaire, underwent otoscopic and tympanometric examinations, and determined preferred music volumes in an audiometry booth using calibrated music samples of their preferred genres. Hearing thresholds up to 16 kiloHertz (kHz) were measured. Daily music exposure for each participant was normalized to 8 h to calculate a time-weighted average of 8 h (TWA8). Total exposure (TE) was calculated by multiplying TWA8 by the number of years of music listening. RESULTS: A total of 32.4% of participants had TWA8s above 65 dB. Their hearing thresholds at 125, 250, 500, and 16,000 Hz and the average of 125 Hz-8 kHz were significantly higher. Participants with TWA8s above 65 dB were also more prone to speaking loudly and experiencing communication difficulties on the phone. Those with a TE of more than 400 experienced significantly more speech discrimination difficulty in noisy environments and temporary hearing loss/tinnitus after exposure to loud music. Participants with a TE above 700 had worse thresholds at 4, 14, and 16 kHz frequencies, as well as 125-8000 Hz and 500-4000 Hz averages compared to those with a TE below 700. CONCLUSIONS: This study provides evidence that recreational music with much lower exposure levels than the universally accepted TWA8 of 85 dB could negatively impact hearing in healthy young adults. Therefore, maintaining a maximum TWA8 of 65 dB is recommended.

Face the (unamplified) music: Key findings for musicians.

Music is complex. There are risks to hearing health associated with playing due to excessive sound exposure. Face the Music is an on-going cross-sectional project to assess the risks to unamplified classical musicians. Key findings over the first fifteen years are presented based on the research undertaken with a leading conservatoire on more than 5000 classical music students. The work covers hearing health surveillance, education and awareness, sound exposure, and new technology. The future of the research programme is discussed along with opportunities in objective hearing health assessment and new acoustic solutions. A lot has changed in fifteen years, but the research was driven by a change in United Kingdom legislation. It is hoped that the research results can inform future regulation.

Frequency-dependent temporary threshold shifts in the Eastern painted turtle (Chrysemys picta picta).

Testudines are a highly threatened group facing an array of stressors, including alteration of their sensory environment. Underwater noise pollution has the potential to induce hearing loss and disrupt detection of biologically important acoustic cues and signals. To examine the conditions that induce temporary threshold shifts (TTS) in hearing in the freshwater Eastern painted turtle (Chrysemys picta picta), three individuals were exposed to band limited continuous white noise (50-1000 Hz) of varying durations and amplitudes (sound exposure levels ranged from 151 to 171 dB re 1 µPa2 s). Control and post-exposure auditory thresholds were measured and compared at 400 and 600 Hz using auditory evoked potential methods. TTS occurred in all individuals at both test frequencies, with shifts of 6.1-41.4 dB. While the numbers of TTS occurrences were equal between frequencies, greater shifts were observed at 600 Hz, a frequency of higher auditory sensitivity, compared to 400 Hz. The onset of TTS occurred at 154 dB re 1 µPa2 s for 600 Hz, compared to 158 dB re 1 µPa2 s at 400 Hz. The 400-Hz onset and patterns of TTS growth and recovery were similar to those observed in previously studied Trachemys scripta elegans, suggesting TTS may be comparable across Emydidae species.

Risk analysis of noise-induced hearing loss of workers in the automobile manufacturing industries based on back-propagation neural network model: a cross-sectional study in Han Chinese population.

OBJECTIVES: This study aims to predict the risk of noise-induced hearing loss (NIHL) through a back-propagation neural network (BPNN) model. It provides an early, simple and accurate prediction method for NIHL. DESIGN: Population based, a cross sectional study. SETTING: Han, China. PARTICIPANTS: This study selected 3266 Han male workers from three automobile manufacturing industries. PRIMARY OUTCOME MEASURES: Information including personal life habits, occupational health test information and occupational exposure history were collected and predictive factors of NIHL were screened from these workers. BPNN and logistic regression models were constructed using these predictors. RESULTS: The input variables of BPNN model were 20, 16 and 21 important factors screened by univariate, stepwise and lasso-logistic regression. When the BPNN model was applied to the test set, it was found to have a sensitivity (TPR) of 83.33%, a specificity (TNR) of 85.92%, an accuracy (ACC) of 85.51%, a positive predictive value (PPV) of 52.85%, a negative predictive value of 96.46% and area under the receiver operating curve (AUC) is: 0.926 (95% CI: 0.891 to 0.961), which demonstrated the better overall properties than univariate-logistic regression modelling (AUC: 0.715) (95% CI: 0.652 to 0.777). The BPNN model has better predictive performance against NIHL than the stepwise-logistic and lasso-logistic regression model in terms of TPR, TNR, ACC, PPV and NPV (p<0.05); the area under the receiver operating characteristics curve of NIHL is also higher than that of the stepwise and lasso-logistic regression model (p<0.05). It was a relatively important factor in NIHL to find cumulative noise exposure, auditory system symptoms, age, listening to music or watching video with headphones, exposure to high temperature and noise exposure time in the trained BPNN model. CONCLUSIONS: The BPNN model was a valuable tool in dealing with the occupational risk prediction problem of NIHL. It can be used to predict the risk of an individual NIHL.

Prevalence and associated factors of noise-induced hearing loss among workers in Bishoftu Central Air Base of Ethiopia.

Excessive occupational exposure to noise results in a well-recognized occupational hearing loss which is prevalent in many workplaces and now it is taken as a global problem. Therefore, this study aims to assess the prevalence of noise-induced hearing loss and associated factors among workers in the Bishoftu Central Air Base in Ethiopia. An institutional-based cross-sectional study was conducted among 260 central air base workers through face-to-face interviews, an environment noise survey, and an audiometric test for data collection. Data were entered by Epi-data version 3.1 and SPSS was used to analyze the data. Finally, a statistical analysis such as descriptive and binary logistic regression analysis was applied. A P-value < 0.05 at 95% CI was considered statistically significant. The overall prevalence of noise-induced hearing loss and hearing impairments was 24.6 and 30.9%, respectively. The highest prevalence of noise-induced hearing loss was recorded for workers who were exposed to noise levels greater than 90 dBA. Out of 132 workers exposed to the average noise level of 75 dB A, only 5% of workers were affected with noise-induced hearing loss, while 128 workers exposed to an average noise level equal to or greater than 90 dB A, 19.6% of workers were identified with noise-induced hearing loss. Regarding sex, around 21.9% of male workers were identified with noise-induced hearing loss. Workers who were exposed to a high noise level workplace previously or before the Central Air Base workplace were five times (AOR = 5.0, 95% CI 1.74-14.36) more likely affected by noise-induced hearing loss than those workers not previously exposed. Those workers who were exposed to greater or equal to 90dBA noise level were 4.98 times (AOR = 4.98, 95% CI 2.59-9.58) more likely to be exposed to noise-induced levels than those who were exposed to less than 90dBA noise level. Moreover, male air base workers were 3.5 times more likely exposed to hearing impairment than female workers (AOR = 3.5, 95% CI 1.01-12.0). This study identified that the prevalence of noise-induced hearing loss and hearing impairments was significantly high. So implementation of a hearing conservation program, giving noise education, and supplying adequate hearing protective devices (HPDs) are essentials.

Effects of Occupational Noise Exposure on Hearing Loss: Regulatory Effect of Mediterranean Diet.

OBJECTIVE: To assess regulatory effect of Mediterranean diet for occupational noise exposure and hearing loss. Methods: This cross-sectional study included 4757 individuals. Weighted logistic regression model was adopted to explore the association of occupational noise exposure and Mediterranean diet with hearing loss, and regulatory effects of the Mediterranean diet for the relationship of occupational noise exposure and hearing loss. Results: Occupational noise exposure was associated with an increased odds of hearing loss. Under low adherence to the Mediterranean diet, the occupational noise exposure group was related to increased odds of hearing loss. Under high adherence to the Mediterranean diet, no significant difference was observed between occupational noise exposure and hearing loss, and adjusted effect size was reduced accordingly. Conclusion: Mediterranean diet may moderate this relationship of occupational noise exposure and hearing loss to some degree.

Synaptic ribbon dynamics after noise exposure in the hearing cochlea.

Moderate noise exposure induces cochlear synaptopathy, the loss of afferent ribbon synapses between cochlear hair cells and spiral ganglion neurons, which is associated with functional hearing decline. Prior studies have demonstrated noise-induced changes in the distribution and number of synaptic components, but the dynamic changes that occur after noise exposure have not been directly visualized. Here, we describe a live imaging model using RIBEYE-tagRFP to enable direct observation of pre-synaptic ribbons in mature hearing mouse cochleae after synaptopathic noise exposure. Ribbon number does not change, but noise induces an increase in ribbon volume as well as movement suggesting unanchoring from synaptic tethers. A subgroup of basal ribbons displays concerted motion towards the cochlear nucleus with subsequent migration back to the cell membrane after noise cessation. Understanding the immediate dynamics of synaptic damage after noise exposure may facilitate identification of specific target pathways to treat cochlear synaptopathy.