Noise and hearing loss: a review

Association of Occupational Noise Exposure and Extended High-Frequency Hearing Loss in Young Workers With Normal Hearing

OBJECTIVES

Studies on the relationship between occupational noise exposure and extended high-frequency (EHF) hearing loss are limited. This study investigated the relationship between occupational noise exposure and EHF hearing loss in workers exposed to noise as measured by sound pressure level, exposure duration, and kurtosis to help provide a basis for early detection and prevention of hearing loss in noise-exposed workers.

DESIGN

A cross-sectional survey was conducted among 602 participants with 472 noise-exposed workers and 130 non-noise-exposed controls. General demographic characteristics, noise exposure data, and hearing thresholds at conventional frequencies (0.25 to 8 kHz) and EHF (9 to 16 kHz) were collected and analyzed. Linear mixed-effects model analyses between hearing thresholds of EHF and noise exposure indicators including the 8-h equivalent continuous A-weighted sound pressure level ( LAeq,8h ), cumulative noise exposure (CNE), and kurtosis-adjusted CNE (CNE-K) were conducted.

RESULTS

Among the 602 participants included in the analysis, 472 individuals (78.4%) were occupationally exposed to noise exposures ≥75 dBA. Significant differences ( p < 0.05) were observed in sex, exposure duration, LAeq,8h , CNE, and CNE-K between the noise-exposed group and the nonexposed group. The mean hearing thresholds for all tested extended high frequencies ranging from 9 to 16 kHz were significantly higher in the noise-exposed group than in the nonexposed group ( p < 0.05). The mean hearing thresholds of subjects in different groups of LAeq,8h exposures were generally stable with little variance in the conventional frequencies (0.25 to 8 kHz) but differed in the EHF range. Moreover, EHF hearing loss appeared to be most prominent in the subjects exposed to noise with 80 dBA < LAeq,8h ≤ 85 dBA. After the combination of the sound pressure level, exposure duration, and kurtosis by using the noise exposure indicators CNE and CNE-K, the subjects at the different noise exposures showed significant differences in hearing thresholds at EHF ( p < 0.05). Linear mixed-effected model analyses showed that the CNE-K was the best to indicate noise-induced hearing loss among the three noise exposure indicators at EHF.

CONCLUSIONS

The results indicate that the EHF hearing threshold testing is more sensitive to identifying early occupational noise-induced hearing loss than conventional audiometry. The CNE-K, an indicator combining noise energy, exposure duration, and kurtosis, is a more comprehensive and effective method for assessing the risk of EHF hearing loss due to occupational noise exposure.

The Prevalence, Knowledge, Attitude, and Practice of Occupational Hearing Loss Among Industrial Workers in Saudi Arabia

PURPOSE

Occupational noise poses a persistent hazard to hearing, while lack of awareness and inadequate hearing protection device (HPD) training heighten the risk of noise-induced hearing loss (NIHL). Few studies have investigated the effects of NIHL and HPD use in Saudi Arabia, with only one in Jeddah. Therefore, this study aimed to estimate the prevalence of occupational NIHL and assess workers' knowledge, attitudes, and practices (KAP) regarding HPDs in Jeddah, Saudi Arabia.

METHOD

This cross-sectional study included 200 industrial workers aged 18-55 years who were exposed to noise. Data were analyzed using descriptive and inferential statistics, including correlations and chi-squared tests. A 32-item questionnaire assessed the KAP regarding occupational NIHL and HPD usage. Hearing screening was conducted using pure-tone audiometry at 0.5, 1, 2, 3, 4, 6, and 8 kHz. Participants who failed screening underwent a comprehensive audiological evaluation.

RESULTS

The analysis revealed that 39.5% of the participants failed hearing screening. Regarding participants' knowledge, 82% believed that noise could affect hearing, 64.5% believed that NIHL could be prevented, and only 35% knew that it was permanent. In terms of HPD usage, 49% always wore them and 34% wore them sometimes. The main reason for not using HPDs was the difficulty communicating with others while wearing them (40%).

CONCLUSIONS

Findings revealed that the prevalence of occupational NIHL was higher than the global prevalence. Thus, hearing conservation programs and enhanced awareness of the permanent nature of NIHL can encourage HPD utilization, which is crucial for preventing diminished productivity, income, and overall quality of life.

[Chronic tinnitus from a psychological perspective]

Chronic tinnitus is a common and often highly distressing phenomenon that, in its chronic phase, is primarily maintained by psychological factors. Individuals affected by tinnitus frequently attribute fluctuations in their emotional well-being causally to the tinnitus symptom. However, from a psychotherapeutic perspective, both the perception of symptoms and the resulting emotional distress are shaped by complex, dynamic interactions involving (a) personal life experiences, (b) personality traits, (c) the subjective interpretation of intrapsychic and interpersonal stimuli, (d) emotional states, and (e) coping strategies at both intrapsychic and interpersonal levels. This review begins with a brief introduction and then connects a well-established psychological theory of chronic tinnitus development and maintenance with a broader vulnerability-stress-coping model. Within this framework, we present key research findings from both somatic and psychological perspectives, ultimately offering insights for psychotherapeutic prevention and treatment approaches.

Hybrid statistical and machine-learning approach to hearing-loss identification based on an oversampling technique

BACKGROUND AND OBJECTIVES

Hearing loss is a crucial global health hazard exerting considerable social and physiological effects on spoken language and cognition. Patients affected by this condition may experience social and professional hardships that dominate occupational injuries. Therefore, the identification of the features of recessive hearing loss is important for clinicians to prevent further disease progression. This work aimed to develop a hybrid statistical and machine-learning approach as a decision-support mechanism. We expect the proposed model to help predict hearing-loss disorders and support clinical diagnosis.

METHODS

A three-phase hybrid approach was proposed to implement classification models. A stepwise method and a random forest (RF) technique were utilized as filters during feature selection. Phase I involved reducing the number of input variables and selecting the most influential features. Phase II included the use of an oversampling technique called synthetic minority oversampling technique (SMOTE) to oversample the minority class and balance the sample size between the target and nontarget classes. Phase III focused on the final model selection based on three supervised classification models, namely, the logistic regression, multilayer perceptron, and support vector machine (SVM), for the target identification and prediction of the case of interest (i.e., hearing loss).

RESULTS

The analysis of phase I involved the selection and acquisition of three and seven features through the stepwise technique and RF method, respectively. The SMOTE technique alleviated the imbalanced data issue and improved the predictive capability substantially in phase II and III. Accordingly, in terms of accuracy, precision, recall, and F1 score, our empirical results demonstrated that the proposed hybrid approach involving the SVM method combined with a stepwise technique was competitive against the logistic model featuring all variables. Furthermore, the SVM models that cooperated with the stepwise and RF technique showed superiority to other approaches in terms of the area under the curve (AUC).

CONCLUSION

Compared with multivariate models, the hybrid approach combining the SVM method coupled with a stepwise technique and/or an RF technique is an excellent alternative with a higher efficiency. This approach requires fewer predictors in the model and can be competitive in terms of the accuracy, precision, recall, F1 score, and AUC. This work highlights the potential of hybrid statistical and machine-learning approaches. Our model can be used as a screening tool for upfront forecasting in clinical practice. The proposed hybrid approach also demonstrates a powerful capability to identify vital features and predict hearing loss.

A systematic analysis of the burden of disease attributable to occupational noise-induced hearing loss in China based on the 2019 global burden of disease study

BACKGROUND

Occupational noise has long been recognized as a significant risk factor for hearing loss, particularly among workers. This study aimed to assess the disease burden of hearing loss caused by occupational noise in China from 1990 to 2019, with a focus on differences across sex and age groups, so as to address the existing gaps in the Global Burden of Disease Study (GBD) reports. By analyzing changes in years lived with disability (YLDs) among different sex and age groups over the past 30 years, this study provides valuable insights for the development of occupational noise safety measures in China.

METHODS

We extracted data on the burden of hearing loss attributable to occupational noise from the 2019 Global Burden of Disease study. R software (version 4.12) was used to calculate the YLDs, age-standardized rates (ASRs), and average annual percent change (AAPC), stratified by age and sex. The Joinpoint regression model was used to analyze the trends in the burden of disease attributable to occupational noise exposure from 1990 to 2019.

RESULTS

In China, the YLDs attributable to occupational noise-induced hearing loss in 2019 were 2.3277 million [95% uncertainty interval (UI): 1.5779-3.3478 million, marking a 70.95% increase compared with that in 1990. Throughout the study period, YLD rates exhibited a declining trend, with rates of 127.7 per 100,000 (95% UI: 87.4-181.4) in 1990 and 119.8 per 100,000 (95% UI: 81.2-182.1) in 2019. Using the Joinpoint regression model, the annual percent change (APC) in age-standardized YLD rates for occupational noise-related hearing loss initially increased from 1990 to 2000, followed by a decline, reaching its lowest point in 2015. From a sex perspective, the burden of YLDs in Chinese males exceeded that in females, although the rate of decline was less pronounced in females. With regard to age, the number and rate of YLDs attributable to occupational noise-induced hearing loss generally increased with age, particularly among middle-aged individuals and older adults. However, from 1990 to 2019, the number of YLDs attributable to occupational noise-induced hearing loss decreased among young people aged 15-19 years, accompanied by a significant reduction in YLDs rates.

CONCLUSION

Hearing loss attributable to occupational noise represents a substantial public health concern, especially among middle-aged and older adult workers in China. These findings underscore the importance of implementing effective measures to mitigate occupational noise exposure.

An intense electrical stimulus can elicit a StartReact effect but with decreased incidence and later onset of the startle reflex

Planned actions can be triggered involuntarily by a startling acoustic stimulus (SAS), resulting in very short reaction times (RT). This phenomenon, known as the StartReact effect, is thought to result from the startle-related activation of reticular structures. However, other sensory modalities also can elicit a reflexive startle response. Here, we assessed the effectiveness of an intense startling electric stimulus (SES) in eliciting the StartReact effect as compared to a SAS. We tested SES intensities at 15 and 25 times the perceptual threshold of each participant, as well as SAS intensities of 114 dB and 120 dB. The electrical stimulation electrodes were placed over short head of the biceps brachii on the arm not involved in the task. Intense electric and acoustic stimuli were presented on 20% of the trials in a simple RT paradigm requiring a targeted ballistic wrist extension movement. The proportion of trials showing short latency (≤ 120 ms) startle reflex-related activation in sternocleidomastoid was significantly lower on intense electrical stimulus trials compared to intense acoustic trials, and the startle response onset occurred significantly later on SES trials compared to SAS. However, when a startle reflex was observed, RTs related to the prepared movement were facilitated to a similar extent for both SES and SAS conditions, suggesting that the accelerated response latency associated with the StartReact effect is independent of stimulus type.

Effects of cultural dynamics on everyday acoustic environmentsa)

Differences in acoustic environments have previously been linked to socioeconomic status (SES). However, it is crucial to acknowledge that cultural values can also play a significant role in shaping acoustic environments. The goal of this study was to investigate if social behaviors related to cultural heritage and SES could help us understand how Latinx and European college students in the U.S. have different acoustic environments. College students were given digital recorders to record their daily acoustic environments for two days. These recordings were used to (1) evaluate nearfield noise levels in their natural surroundings and (2) quantify the percentage of time participants spent on behavioral collectivistic activities such as socializing and interacting with others. Behavioral collectivism was examined as a mediator between cultural heritage, SES, and nearfield noise levels. Findings revealed that both SES and cultural heritage were associated with nearfield noise levels. However, behavioral collectivism mediated the relationship between culture and nearfield noise levels. These findings show that collectivist cultural norms significantly relate to Latinx' daily noise levels. The implications of these findings for public health and health inequities included promoting equitable auditory well-being and better knowledge of socio-cultural settings.

Factors Influencing Intentions of People with Hearing Impairments to Use Augmented Reality Glasses as Hearing Aids

The advent and progression of AR (augmented reality) technology, coupled with the emergence of AR hearing aid glasses, offer a novel opportunity for people with hearing impairments (PHI). This study aims to explore the intention of this population to employ AR hearing aid glasses as their choice of hearing aid device and the specific factors influencing their preference. This study utilized the partial least squares SEM (PLS-SEM) analytical method to create structural equation model for intentions of PHI to use AR glasses as hearing aids. Data were gathered from on-site experiences across multiple locations; a total of 189 valid questionnaires from individuals with varying degrees of hearing disabilities were used for statistical analysis. According to the data analysis results, we discovered that functionality quality, perceived interaction speed, and perceived usability significantly influence communication effectiveness. Further, communication effectiveness positively influences confidence and societal perception, and the latter has a positive impact on information. Both of these factors positively influence behavioral intention. Based on these findings, this study offers design recommendations for AR hearing aid glasses to cater to the specific needs of PHI, aiming to enhance their quality of life. Furthermore, this study provides pivotal insights for the prospective growth of this emerging industry.

Noise exposure assessment of workers inspecting construction machinery vehicles in the Republic of Korea

Previous studies have investigated the health hazards caused by exposure to the noise of heavy equipment used at construction sites. Korea's Ministry of Land, Infrastructure, and Transport operates a registration system for construction machinery, and regular safety inspections are mandatory. Although workers inspecting construction machinery vehicles are exposed to unwanted noise, no noise exposure assessment has been made regarding these workers in Korea. The time-weighted average (TWA) daily average noise exposure level among construction machinery inspectors at 18 inspection centers was 75.3 dB(A). Among the inspection steps, the exhaust gas inspection step was found to exhibit the highest noise exposure level, up to 100 dB(A). In Korea, if the noise level of a workplace exceeds 85 dB(A) as a TWA, workers are required to undergo special medical examinations. This study found that special medical examinations were required for two of the 18 target inspection centers (approximately 115 workers) as the 8-hour TWA noise level exceeded 85 dB(A). Therefore, regular noise exposure assessment and special medical examinations for noise are required to prevent inspectors from developing hearing disorders due to noise exposure.

Effects of noise exposure on stress hormone changes during task performance in young Korean men: quasi-experimental study

Numerous studies have suggested that noise exposure might be associated with changes in stress hormone levels. However, quantitative evidence for these effects in humans is rare and remains controversial. This study aimed to investigate the acute effects of exposure to noise and its different levels on stress hormone changes in task performance. Quasi-experimental noise exposure environment was established for 90 male university student volunteers in their twenties, and each was exposed to different noise levels during task performance. The stress hormones tested included cortisol, adrenocorticotropic hormone (ACTH), adrenaline, and noradrenaline. A one-way ANOVA was performed to investigate differences in hormone levels measured in the three groups according to the noise exposure levels (35, 45, or 75 dB). Analysis of covariance (ANCOVA) was used to adjust for confounding factors that might affect hormone levels. After adjusting for confounders, significant exposure-dependent differences were found in hormone levels in salivary cortisol, serum cortisol, serum ACTH, and serum adrenaline. The amount of hormonal increase in 75 dB exposure group compared to 35 or 45 dB groups was detected. Similar results were also seen in the rate of change analysis. Our findings indicate that short-term noise exposure during task performance elevates stress hormone levels. Further, the extent of stress hormone alterations varies with noise exposure levels. Changes in hormone levels are an objective measure that may be used to identify health effects and stress responses in various noise environments.

Traffic Noise Impacts Glucocorticoid Response, Activity, and Growth in Two Species of Tadpoles

There is a large body of evidence linking increased noise to negative health effects for animals. Anthropogenic noise induces behavioral and physiological reactions across a range of taxa and increased traffic noise affects glucocorticoid (GC) hormones associated with the stress response in amphibians. GCs help to maintain homeostasis while balancing energetic trade-offs between reproduction, growth, and activity. Stressors during early development can impact fitness at later life stages. We measured growth, activity, and GCs in response to high levels of traffic noise in two tadpole species that differ in life history: Acris crepitans and Rana berlandieri. We predicted that earlier exposures to traffic noise will slow down the development and alter the behavior and GC concentrations differently than later exposures. Subjects were initially either exposed to natural levels of traffic noise for 8 days (early exposure) or a white noise control (later exposure), then the treatment was switched. Activity was measured via focal sampling and tadpoles were categorized as active if movement was detected. Tadpoles exposed to white noise initially maintained mass and activity throughout the experiment and early exposure to traffic noise had a greater impact on mass, activity, and GCs. Tadpoles exposed to traffic noise initially lost mass, with A. crepitans regaining mass but not R. berlandieri. When exposed earlier to traffic noise, R. berlandieri increased movement when shifted to the white noise treatment while A. crepitans did not significantly change activity. Acris creptians had higher corticosterone release rates compared to R. berlandieri, and in both species, release rates were higher for tadpoles exposed to noise earlier. The longer-lived R. berlandieri allocated more of their energetic resources into activity, while the shorter-lived A. crepitans allocated energy toward growth. Rana berlandieri and A. crepitans utilized different coping strategies to contend with early exposure to traffic noise, potentially due to differences in life histories. Our findings suggest that these tadpoles employ different coping mechanisms to modulate stress responses in noise-polluted environments, and these mechanisms could influence their fitness later in life. Further study is needed to understand the impact in more sensitive tadpole species.

Occupational noise-induced hearing loss among dental personnel: a scoping review

Introduction Dental personnel are being exposed to noisy equipment on a daily basis and there are indications that dental professionals are at a higher risk of developing occupational noise-induced hearing loss (NIHL). Therefore, this study aims to assess the available research on NIHL among dental professionals.Methods A total of 452 publications were identified through searches on PubMed and Web of Science. These studies were screened on title and abstract for studies that investigated NIHL among dental professionals using objective or subjective parameters for hearing loss. The remaining publications were then searched for relevant data, such as research type, parameters used for measuring hearing loss and authors' conclusions.Results In total, 28 publications were finally included in the selection. Of this selection, 23 used objective criteria for NIHL, three used subjective criteria and two used both. From the 12 studies with objective measurements that also included a control group in their studies, eight reported a significant higher hearing loss among dental personnel than in the control groups. From the 13 studies with objective measurement without a control group, seven reported significant hearing loss among dental personnel. All five studies with subjective measurements reported significant hearing loss in dental personnel.Conclusions Hearing loss seems to be more prevalent among dental personnel than in most control groups.

Utilizing Artificial Neural Networks for Establishing Hearing-Loss Predicting Models Based on a Longitudinal Dataset and Their Implications for Managing the Hearing Conservation Program

Background

Though the artificial neural network (ANN) technique has been used to predict noise-induced hearing loss (NIHL), the established prediction models have primarily relied on cross-sectional datasets, and hence, they may not comprehensively capture the chronic nature of NIHL as a disease linked to long-term noise exposure among workers.

Methods

A comprehensive dataset was utilized, encompassing eight-year longitudinal personal hearing threshold levels (HTLs) as well as information on seven personal variables and two environmental variables to establish NIHL predicting models through the ANN technique. Three subdatasets were extracted from the afirementioned comprehensive dataset to assess the advantages of the present study in NIHL predictions.

Results

The dataset was gathered from 170 workers employed in a steel-making industry, with a median cumulative noise exposure and HTL of 88.40 dBA-year and 19.58 dB, respectively. Utilizing the longitudinal dataset demonstrated superior prediction capabilities compared to cross-sectional datasets. Incorporating the more comprehensive dataset led to improved NIHL predictions, particularly when considering variables such as noise pattern and use of personal protective equipment. Despite fluctuations observed in the measured HTLs, the ANN predicting models consistently revealed a discernible trend.

Conclusions

A consistent correlation was observed between the measured HTLs and the results obtained from the predicting models. However, it is essential to exercise caution when utilizing the model-predicted NIHLs for individual workers due to inherent personal fluctuations in HTLs. Nonetheless, these ANN models can serve as a valuable reference for the industry in effectively managing its hearing conservation program.

Associations between dietary indices and hearing status among middle-older aged adults - results from the Baltimore Longitudinal Study of Aging

BACKGROUND

Hearing loss, a public health issue in older populations, is closely related to functional decline.

OBJECTIVE

To investigate the longitudinal associations between 4 dietary indices and hearing status.

METHODS

Data from the Baltimore Longitudinal Study of Aging were used and included 882 participants ≥45 y of age. Dietary intake was assessed using a validated food frequency questionnaire, and 4 dietary scores (Mediterranean-Dietary Approaches to Stop Hypertension Intervention for Neurodegenerative Delay diet [MIND], Mediterranean style diet score [MDS], Alternative Healthy Eating Index [AHEI], and Healthy Eating Index [HEI]) were calculated as averages over time. Hearing status was examined using pure-tone audiometry, and pure-tone average (PTA) of hearing thresholds were calculated at speech-level (PTA(500, 1000, 2000, 4000 Hz)), low (PTA(500, 1000 Hz)), and high (PTA(4000, 8000 Hz)) frequencies, with lower thresholds indicating better hearing. Multivariable linear mixed-effect models were used to examine associations between dietary indices and hearing threshold change over time adjusted for confounders.

RESULTS

At baseline, the mean age of participants was 67 y and 55% were female. Over a median of 8 y of follow-up, MDS ≥7 was associated with 3.5 (95% CI: -6.5, -0.4) and 5.0 (95% CI: -9.1, -1.0) dB lower PTA(500, 1000, 2000, 4000 Hz) and PTA(4000, 8000 Hz), respectively, compared with MDS ≤3; the highest tertile of the AHEI was associated with 2.3 (95% CI: -4.6, -0.1) and 5.0 (95% CI: -8.0, -2.0) dB lower PTA(500, 1000, 2000, 4000 Hz) and PTA(4000, 8000 Hz); and each standard deviation increment in HEI was associated with 1.6 dB (95% CI: -2.7, -0.6), 1.1 dB (95% CI: -2.1, -0.1), and 2.1 dB (95% CI: -3.5, -0.6) lower PTA(500, 1000, 2000, 4000 Hz), PTA(500, 1000 Hz), and PTA(4000, 8000 Hz), respectively.

CONCLUSIONS

Adherence to healthy dietary patterns was associated with better hearing status, with stronger associations at high frequencies. Am J Clin Nutr 20xx;x:xx.

Prevalence and Associated Factors of Sensorineural Hearing Impairment Among Patients with T2DM in Amhara Region, Northwest Ethiopia, 2022: A Multi-Centered Cross-Sectional Study

Background

Generally, people with type 2 diabetes mellitus in various countries experience a significant rate of sensorineural hearing impairment. Nonetheless, there is scant evidence of sensorineural hearing impairment among type 2 diabetes mellitus patients in Northwest Ethiopian. Therefore, the objective of this study was to evaluate the occurrence rate and contributing factors of sensorineural hearing impairment in type 2 diabetics at comprehensive and specialized referral hospitals in Northwest Ethiopia.

Methods

A facility-based cross-sectional study design was carried out from May 3, 2022, to June 14, 2022, on 846 study participants in Ethiopia, with a response rate of 99.65%. The research subjects were chosen by simple random sampling techniques. Data was gathered by using audiometric measurements and structured interview-administered questionnaires and then entered into EPI data version 4.6. Finally, it was exported to STATA 14 for analysis. Binary logistic regression, chi-square test, and odds ratio were done to verify the assumptions and degree of association. Ultimately, factors exhibiting a p-value < 0.05 with a 95% CI were regarded as significant predictors of hearing impairment.

Results

The magnitude of sensorineural hearing impairment in this investigation was 50.49% (95% CI: 45.67%, 55.26%). Factors significantly associated with sensorineural hearing impairment were age (AOR=1.10, 95% CI: 1.07, 1.14), hyperlipidemia (AOR=2.86, 95% CI: 1.05, 7.82), duration of diabetes (AOR=2.26, 95% CI: 1.26, 4.06), hypertension (AOR=1.94, 95% CI: 1.02, 3.69) and regular physical exercise (AOR=0.25, 95% CI: 0.09, 0.68).

Conclusions and Recommendations

In this study, relatively high rates of sensorineural hearing impairment were observed. Stakeholders should establish routine hearing screening, and participants will advise to incorporate regular physical exercise into their routines.

Role of Oxidative Stress in Sensorineural Hearing Loss

Hearing is essential for communication, and its loss can cause a serious disruption to one's social life. Hearing loss is also recognized as a major risk factor for dementia; therefore, addressing hearing loss is a pressing global issue. Sensorineural hearing loss, the predominant type of hearing loss, is mainly due to damage to the inner ear along with a variety of pathologies including ischemia, noise, trauma, aging, and ototoxic drugs. In addition to genetic factors, oxidative stress has been identified as a common mechanism underlying several cochlear pathologies. The cochlea, which plays a major role in auditory function, requires high-energy metabolism and is, therefore, highly susceptible to oxidative stress, particularly in the mitochondria. Based on these pathological findings, the potential of antioxidants for the treatment of hearing loss has been demonstrated in several animal studies. However, results from human studies are insufficient, and future clinical trials are required. This review discusses the relationship between sensorineural hearing loss and reactive oxidative species (ROS), with particular emphasis on age-related hearing loss, noise-induced hearing loss, and ischemia-reperfusion injury. Based on these mechanisms, the current status and future perspectives of ROS-targeted therapy for sensorineural hearing loss are described.

B. A Survey of Knowledge and Attitude of College Students Toward Hearing Loss Prevention

BACKGROUND

College students risk hearing loss due to loud sound exposure during leisure activities. Hearing loss prevention is possible by reducing the noise from the source, using hearing protection devices and increasing their knowledge and awareness on the effects of loud sound exposure.

OBJECTIVE

The study aims to assess the knowledge and attitude of college students regarding hearing loss and its prevention.

STUDY DESIGN

A cross-sectional study design with a survey method was adopted. A total of 94 college students (mean age: 22 years; range: 18 to 26) who were pursuing an undergraduate and postgraduate degree (50 males and 44 females) formed the part of the study. The researcher administered a standardized self-reported Knowledge, Attitude and Behaviour questionnaire. The knowledge score in percentage and absolute scores for attitude were estimated.

RESULTS

The mean knowledge score was 35.8 (SD ± 12.18; range: 12.5-75), and the attitude score was + 9.8 (SD ± 7.1; range: - 4 to + 30). Chi square test revealed no significant association between knowledge and attitude to sociodemographic characteristics.

CONCLUSION

 The study indicated that though college students lack knowledge, they had a positive attitude regarding hearing health and its protection. These findings implicate the importance of creating awareness and encouraging hearing protection strategies for college students.

Effects of Astragaloside IV on Hearing, Inflammatory Factors, and Intestinal Flora in Mice Exposed to Noise

Long-term exposure to noise can cause irreversible hearing loss. Considering that there is no effective drug treatment, it is important to seek preventive treatment for noise-induced hearing loss (NIHL). Although astragaloside IV (AS-IV) protects against NIHL by reducing serum inflammatory factors, there is scarce information on the regulation of inflammatory factors by AS-IV to prevent NIHL. We investigated the hearing thresholds and relationship between the serum levels of inflammatory cytokines and intestinal microbiota of c57bl/6j mice exposed to noise (103 dB SPL 4 h·d-1) for 7 days, treated with or without AS-IV. Our results revealed a lower hearing threshold and lower serum levels of TNF-α, TNF-γ, IL-6, IL-1β, and IFN-γ in the mice treated with AS-IV. Additionally, AS-IV increased the abundance levels of the phylum Firmicutes, class Bacillus, order Lactobacillus, and family Lactobacillus (p < 0.05), and decreased those of the phylum Bacteroidetes and order Bacteroidales (p < 0.05). Lactobacillus and Bacilli negatively correlated with TNF-α, TNF-γ, and IL-1β; Erysipelotrichaceae negatively correlated with INF-γ; and Clostridiales positively correlated with IL-1β. In conclusion, AS-IV reduces the elevation of hearing thresholds in mice, preventing hearing loss in mice exposed to noise, and under the intervention of AS-IV, changes in the levels of inflammatory factors correlate with intestinal flora. We suggest that AS-IV improves intestinal flora and reduces inflammation levels in c57bl/6j mice exposed to noise.

The sound of safety: exploring the determinants of prevention intention in noisy industrial workplaces

Occupational noise exposure is a pervasive issue in many industries, leading to a range of health issues and sleep disturbances among workers. Additionally, there is a strong desire among these workers to prevent industrial accidents. This study, aimed at enhancing worker health and well-being, utilized a survey distributed by the Korean Confederation of Trade Unions to field workers. Data from 1285 workers were collected and analyzed using partial least squares structural equation modeling (PLS-SEM) to identify and understand the factors affecting prevention intention in noisy work environments. Our findings indicate that health problems resulting from occupational noise exposure significantly influence insomnia, perceived severity of potential accidents, perceived benefits of preventive measures, and perceived barriers. Perceived severity was significantly correlated with prevention intention, emphasizing the role of risk perception in motivating preventive behaviors. Perceived benefits were also significantly associated with prevention intention, highlighting the importance of positive outcomes in influencing workers' behaviors. Additionally, perceived barriers showed a significant relationship with prevention intention, suggesting that overcoming these barriers is crucial in promoting preventive behaviors. Demographic factors such as gender displayed a significant association with prevention intention, while age did not. This study provides valuable insights into the multifaceted factors influencing workers' intention to prevent industrial accidents in noisy environments, underlining the importance of comprehensive data collection tools in understanding these dynamics.

Residential proximity to major roadways and hearing impairment in Chinese older adults: a population-based study

BACKGROUND

With rapid urban sprawl, growing people are living in the vicinity of major roadways. However, little is known about the relationship between residential proximity to major roadways and hearing impairment (HI).

METHODS

We derived data from the 2018 wave of the Chinese Longitudinal Healthy Longevity Survey, and included 13,775 participants aged 65 years or older. Multivariate logistic regressions were employed to examine the association between residential proximity to major roadways and HI. The effects of corresponding potentially modifiable factors were studied by three-way interaction analyses. Sensitivity analyses were performed to verify the robustness of the results.

RESULTS

The prevalence of HI was 38.3%. Participants living near major roadways were more likely to have a higher socioeconomic status. An exposure-response relation between residential proximity to major roadways and HI was observed (Ptrend < 0.05). Compared with individuals living > 300 m away from major roadways, the adjusted odds ratios (OR) were 1.07 (95% CI: 0.96-1.24), 1.15 (95% CI: 1.07-1.34), and 1.12 (95% CI: 1.01-1.31) for those living 101-200 m, 50-100 m, and < 50 m away from the roadways, respectively. Particularly, the association was more pronounced among individuals exposed to carbon monoxide (CO) pollution or opening windows frequently (Pinteraction < 0.05). Three-way interaction analyses confirmed that participants exposed to CO pollution and frequently leaving windows open had the highest OR of 1.73 (95% CI: 1.58-1.89).

CONCLUSIONS

This nation-wide cohort study suggested that residential proximity to major roadways was significantly associated with an increased exposure-response risk of HI in Chinese older adults. Exposure to CO pollution and opening windows frequently might strengthen the relations.

Risk-taking propensity as a risk factor for noise-induced hearing loss in the general population

OBJECTIVES

To examine general risk propensity in relation to perceptions of noise, risk behaviour, and hearing loss in the general population.

DESIGN

Participants completed an online survey using the Amazon Mechanical Turk crowdsourcing platform.

STUDY SAMPLE

The sample comprised 1274 adults from the United States.

RESULTS

Higher general risk propensity was associated with an increased likelihood to engage in noise-risk behaviours. Lower general risk propensity was associated with increased knowledge of noise risks and an increased perception of noise as risky. The frequency of self-reported exposures to hazardous noise resulted in estimated annual noise doses exceeding standard hazard limits in 40% of the surveyed population.

CONCLUSIONS

Results revealed limited knowledge of the risks and associated health consequences of noise exposure in the general population Results of this study suggest a high rate of self-exposure to hazardous noise by the general population. Those with higher general risk propensity are more likely to engage in risky noise behaviour. Risky noise behaviour is associated with age, gender, race, ethnicity, and general risk propensity. Intervention programs to modify risky noise behaviour in the general population should focus on both increasing knowledge and establishing accurate perceptions of risk.

Task-independent auditory probes reveal changes in mental workload during simulated quadrotor UAV training

Objective

The event-related potential (ERP) methods based on laboratory control scenes have been widely used to measure the level of mental workload during operational tasks. In this study, both task difficulty and test time were considered. Auditory probes (ignored task-irrelevant background sounds) were used to explore the changes in mental workload of unmanned aerial vehicle (UAV) operators during task execution and their ERP representations.

Approach

51 students participated in a 10-day training and test of simulated quadrotor UAV. During the experiment, background sound was played to induce ERP according to the requirements of oddball paradigm, and the relationship between mental workload and the amplitudes of N200 and P300 in ERP was explored.

Main results

Our study shows that the mental workload during operational task training is multi-dimensional, and its changes are affected by bottom-up perception and top-down cognition. The N200 component of the ERP evoked by the auditory probe corresponds to the bottom-up perceptual part; while the P300 component corresponds to the top-down cognitive part, which is positively correlated with the improvement of skill level.

Significance

This paper describes the relationship between ERP induced by auditory probes and mental workload from the perspective of multi-resource theory and human information processing. This suggests that the auditory probe can be used to reveal the mental workload during the training of operational tasks, which not only provides a possible reference for measuring the mental workload, but also provides a possibility for identifying the development of the operator's skill level and evaluating the training effect.

Global, regional, and national prevalence of hearing loss from 1990 to 2019: A trend and health inequality analyses based on the Global Burden of Disease Study 2019

As a severe public health issue, hearing loss has caused an increasingly disease burden, especially in the elderly population. Hearing loss may inevitably induce asymmetric hearing, which makes it difficult for elderly individuals to locate sound sources, therefore resulting in increased postural instability and falling risk. To emphasize the public health emergence of hearing loss, we investigated the temporal trend of prevalence of hearing loss over the last 30 years and further predicted its changes in the next 20 years, decomposed the trend according to demographic factors and epidemiological changes, and quantified the cross-country healthy inequalities, using the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019. In 2019, there were more than 140 million cases of hearing loss worldwide, a 93.89% increase from 70 million cases in 1990. The age-standardized rate (ASR) also increased with an estimated annual percentage change of 0.08% per year. Population growth and aging are the major drivers contributing to the changes, accounting for 60.83% and 35.35%. Of note, the contribution of aging varies showing a gradual increasing trend with sociodemographic index (SDI) elevating. Also notable, there were significant health inequalities across 204 countries and territories, with slope index of inequality rising over time. Projection of the global burden of hearing loss from 2020 to 2040 indicated progressive increases in both case number and ASR. These reflect the heavy disease burden of hearing loss that needed more targeted and efficient strategies in its prevention and management.

[Chronic tinnitus: An interplay between somatic and psychological factors]

Chronic tinnitus is a common, sometimes highly distressing phenomenon that can be triggered and maintained by an interplay of physical and psychological factors. Partnering with clinical psychology and psychosomatic medicine, modern otolaryngology integrates both medical (e.g., hearing loss) and psychological influences (e.g., interactions between biographical experiences, personality traits, subjective evaluation of intrapsychic and interpersonal stimuli, emotional states, and intrapsychic or interpersonal emotion regulation strategies). Both groups of variables can influence the intensity and course of chronic tinnitus symptomatology both directly and indirectly, whereby the quality and relative degrees of psychological and physical components in a person's self-experience can fluctuate. With this in mind, the present article distinguishes between chronic tinnitus symptomatology with or without hearing loss-and strongly advocates for an integrated understanding of the symptomatology within a holistic psychological frame of reference. After a brief introduction to the principles of psychosomatic medicine and psychotherapy, the article discusses psychological case conceptualization using a vulnerability-stress-coping (VSC) model as an example, outlines clinical aspects and diagnostics of chronic tinnitus symptomatology, and concludes with a conceptualization of chronic tinnitus-related distress as a function of person-centered VSC interactions.

Study of fatigue damage to the cochlea

In order to explore the hearing loss resulting from exposure to continuous or intermittent loud noise. A three-dimensional liquid-solid coupling finite element model of spiral cochlea was established. The reliability of the model was verified, and the stress and amplitude of the basilar membrane of the pivotal structure in cochlea were analyzed. The results show that under the action of the same high-pressure sound, the preferential fatigue area of the cochlear high-frequency area mainly causes fatigue in the cochlear. The safer area is a sound pressure level below 70 dB, while one above 90 dB accelerates damage to the ear.

Spatiotemporal Analytics of Environmental Sounds and Influencing Factors Based on Urban Sensor Network Data

Urban construction has accelerated the deterioration of the urban sound environment, which has constrained urban development and harmed people’s health. This study aims to explore the spatiotemporal patterns of environmental sound and determine the influencing factors on the spatial differentiation of sound, thus supporting sustainable urban planning and decision-making. Fine-grained sound data are used in most urban sound-related research, but such data are difficult to obtain. For this problem, this study analyzed sound trends using Array of Things (AoT) sensing data. Additionally, this study explored the influences on the spatial differentiation of sound using GeoDetector (version number: 1.0-4), thus addressing the limitation of previous studies that neglected to explore the influences on spatial heterogeneity. Our experimental results showed that sound levels in different areas of Chicago fluctuated irregularly over time. During the morning peak on weekdays: the four southern areas of Chicago have a high–high sound gathering mode, and the remaining areas are mostly randomly distributed; the sound level of a certain area has a significant negative correlation with population density, park area, and density of bike route; park area and population density are the main factors affecting the spatial heterogeneity of Chicago’s sound; and population density and park area play an essential role in factor interaction. This study has some theoretical significance and practical value. Residents can choose areas with lower noise for leisure activities according to the noise map of this study. While planning urban development, urban planners should pay attention to the single and interactive effects of factors in the city, such as parks, road network structures, and points of interest, on the urban sound environment. Researchers can build on this study to conduct studies on larger time scales.

Community Perspectives on Hearing Loss in Rural Alaska

OBJECTIVES

The aim of this study is to present an explanatory model of hearing loss in the Bering Strait region of Alaska in order to contextualize the results of a cluster randomized trial and propose implications for regional hearing-related health care.

DESIGN

To promote ecological validity, or the generalizability of trial findings to real world experiences, qualitative methods (focus groups and interviews) were used within a mixed methods cluster randomized trial evaluating school hearing screening and follow-up processes in 15 communities in the Bering Strait region of Alaska. Focus groups were held between April and August 2017, and semistructured interviews were conducted between December 2018 and August 2019. Convenience sampling was used for six of the 11 focus groups to capture broad community feedback. Purposive sampling was used for the remaining five focus groups and for all interviews to capture a variety of experiences with hearing loss. Audio recordings of focus groups and interviews were transcribed, and both notes and transcripts were deidentified. All notes and transcripts were included in the analysis. The constant comparative method was used to develop a codebook by iteratively moving between transcripts and preliminary themes. Researchers then used this codebook to code data from all focus groups and interviews using qualitative analysis software (NVIVO 12, QSR International) and conducted thematic analyses to distill the findings presented in this article.

RESULTS

Participants in focus groups (n = 116) and interviews (n = 101) shared perspectives in three domains: etiology, impact, and treatment of hearing loss. Regarding etiology, participants emphasized noise-induced hearing loss but also discussed infection-related hearing loss and various causes of ear infections. Participants described the impact of hearing loss on subsistence activities, while also detailing social, academic, and economic consequences. Participants described burdensome treatment pathways that are repetitive and often travel and time intensive. Communication breakdowns within these pathways were also described. Some participants spoke positively of increased access via onsite hearing health care services in "field clinics" as well as via telemedicine services. Others described weaknesses in these processes (infrequent field clinics and communication delays in telemedicine care pathways). Participants also described home remedies and stigma surrounding the treatment for hearing loss.

CONCLUSIONS

Patient-centered health care requires an understanding of context. Explanatory models of illness are context-specific ways in which patients and their networks perceive and describe the experience of an illness or disability. In this study, we documented explanatory models of hearing loss to foster ecological validity and better understand the relevance of research findings to real-life hearing-related experiences. These findings suggest several areas that should be addressed in future implementation of hearing health care interventions elsewhere in rural Alaska, including management of repetitious treatments, awareness of infection-mediated hearing loss, mistrust, and communication breakdowns. For hearing-related health care in this region, these findings suggest localized recommendations for approaches for prevention and treatment. For community-based hearing research, this study offers an example of how qualitative methods can be used to generate ecologically valid (i.e., contextually grounded) findings.

Noise-Induced Hearing Loss

Noise-induced hearing loss (NIHL) is the second most common cause of sensorineural hearing loss, after age-related hearing loss, and affects approximately 5% of the world's population. NIHL is associated with substantial physical, mental, social, and economic impacts at the patient and societal levels. Stress and social isolation in patients' workplace and personal lives contribute to quality-of-life decrements which may often go undetected. The pathophysiology of NIHL is multifactorial and complex, encompassing genetic and environmental factors with substantial occupational contributions. The diagnosis and screening of NIHL are conducted by reviewing a patient's history of noise exposure, audiograms, speech-in-noise test results, and measurements of distortion product otoacoustic emissions and auditory brainstem response. Essential aspects of decreasing the burden of NIHL are prevention and early detection, such as implementation of educational and screening programs in routine primary care and specialty clinics. Additionally, current research on the pharmacological treatment of NIHL includes anti-inflammatory, antioxidant, anti-excitatory, and anti-apoptotic agents. Although there have been substantial advances in understanding the pathophysiology of NIHL, there remain low levels of evidence for effective pharmacotherapeutic interventions. Future directions should include personalized prevention and targeted treatment strategies based on a holistic view of an individual's occupation, genetics, and pathology.

Risk Factors For Hearing Decline From Childhood To Early Adolescence

OBJECTIVE

To identify risk factors of hearing decline between 9 and 13 years of age. The risk factors examined included sociodemographic, health, and lifestyle-related factors.

METHODS

This study was embedded within a population-based prospective cohort study from fetal life onwards in the Netherlands. Pure-tone audiometry and tympanometry were performed at the age of 9 and 13 years. The hearing decline was defined as an increase in low-frequency or high-frequency pure-tone average of at least 5 dB in one of both ears. Multivariable logistic regression was performed to examine the association of possible risk factors with hearing decline. The study was conducted from April 2012 to October 2015, and from April 2016 to September 2019.

RESULTS

Of the 3,508 participants included, 7.8% demonstrated a hearing decline in the low frequencies, and 11.3% in the high frequencies. Participants who reported alcohol consumption were more likely to have a hearing decline in the low frequencies (OR 1.5, 95% CI 1.1; 2.0). Moreover, a lower educational level was associated with an increased odds of having a hearing decline in the high frequencies (OR 1.4, 95% CI 1.0; 1.8). Age, sex, household income, personal music player use, and body mass index were not associated with hearing decline.

CONCLUSION

Educational level and risky behavior were significantly associated with hearing decline from childhood to early adolescence. The findings of the present study can help in the design of public health interventions to prevent hearing loss at a young age.

LEVEL OF EVIDENCE

2 (prospective cohort study) Laryngoscope, 133:389-395, 2023.

Association of dietary factors with noise-induced hearing loss in Korean population: A 3-year national cohort study

Noise-induced hearing loss (NIHL) is a hearing impairment (HI) caused by various clinical factors. Identifying the relationship between NIHL and nutrient consumption could help in reducing the prevalence of hearing loss. The aim of this study was to analyze the relationship between NIHL and dietary factors using data of the Korea National Health and Nutrition Examination survey (KNHANES). The data were collected from The Fifth KNHANES 2010-2012. The survey was taken by a total of 10,850 participants aged 20-65 years. Air conduction audiometry was measured at 500, 1000, 2000, and 4000 Hz in both ears. Metabolic syndrome, noise exposure, alcohol consumption, smoking, income level, marital status, and nutritional intake were evaluated. The differences between non-HI and HI participants in the noise-exposed group showed statistically significant differences in age, sex, marital and smoking status, alcohol consumption, and fasting glucose and triglyceride levels (p<0.05). In a multiple regression analysis of the noise-exposed group, age showed a significant association with HI (OR: 0.604; 95% CI: 0.538-0.678) after adjusting for confounders. In multivariate analysis for dietary factors affecting HI in noise-exposed groups, retinol (OR: 1.356; 95% CI: 1.068-1.722), niacin (OR: 1.5; 95% CI: 1.022-2.201), and carbohydrates (OR: 0.692; 95% CI: 0.486-0.985) showed a significant association with NIHL. Age was identified as the only factor significantly affecting NIHL. When the dietary factors of the noise-exposed group were analyzed, high intake of niacin and retinol and low intake of carbohydrates appeared to reduce the risk of hearing loss.

Efficacy and safety of antivirals in treating hearing loss: A systematic review and network meta-analysis

Objectives

This study aimed to compare and rank the therapeutic effects of antivirals in treating hearing loss using a network meta-analysis approach.

Methods

We searched the PubMed, Embase, and Cochrane Library databases to identify eligible randomized controlled trials (RCTs) through April 2022. Placebo-controlled or head-to-head RCTs of three categories of antivirals for hearing loss were included, and pooled relative risks (RRs) with 95% confidence interval (CI) were calculated using pairwise and network meta-analyses.

Results

Six RCTs with 405 patients were included in the final analysis. The results showed that ganciclovir had relatively better effects on the incidence of hearing recovery (surface under the cumulative ranking: 88.8%) compared with other antivirals. However, pairwise comparison analyses found that the use of antivirals significantly increased the incidence of hearing recovery compared with the use of a placebo (RR: 1.27; 95% CI: 1.04-1.54; P = 0.017), while no significant difference was observed between any two categories of antivirals. Finally, the use of antivirals did not increase the risk of adverse events compared with the use of a placebo (RR: 1.27; 95% CI: 0.82-1.98; P = 0.285).

Conclusion

Antivirals are more efficacious than placebos for hearing recovery in patients with hearing loss, and ganciclovir is the most likely to increase the incidence of hearing recovery.

Noise and Health: Review

Noise in human societies is unavoidable, but it tends to become a modern epidemic that induces various detrimental effects to several organs and functions in humans. Increased cardiovascular danger, anxiety and sleep disturbance are just few of these effects. It is noteworthy that children, even neonates and their developing organism are especially vulnerable to noise-related health problems. Noise is measured with special noise-meters. These devices express results in decibels by transforming random noise to a continuous sound. This sound is characterized by equivalent acoustic energy to the random noise for a defined time interval. Human auditory apparatus is principally endangered by acute noises but also by chronic noise exposure, in the context of both occupational and recreational activities. Various mechanisms are implicated in the pathogenesis of noise-induced hearing loss that can cause either temporary or permanent damage. Among them, emphasis is given to the impairment by free radicals and inflammatory mediators, to the activation of apoptotic molecular pathways, but also to glutamate excitotoxicity. A hidden hearing loss, synaptopathy, is attributed to the latter. The irreversible nature of hearing loss, as well as the idiosyncratic sensitivity of individuals, imposes the necessity of early diagnosis of auditory impairment by noise. Super high frequency audiograms, otoacoustic emissions and electrophysiological examinations can address diagnosis. Thankfully, there is extensive research on acoustic trauma therapeutic approaches. However, until we succeed in regenerating the sensory organ of hearing, chronic noise-induced hearing loss cannot be treated. Thus, it is fundamental that society protects people from noise, by laws and regulations.

A Prospective Study to Elucidate the Efficacy of 4 Oral Prednisolone Regimens in Acute Acoustic Trauma

Noise induced hearing loss affects around 5% of the population and acoustic trauma to military personnel accounts for 30% of all injuries inflicted during active service. Initial treatment for acoustic trauma involves administration of steroids, however there are no studies regarding oral steroid regimens for best outcomes. Comparing and elucidating the benefits of four oral steroid regimens on hearing gain in patients with acute acoustic trauma. A prospective study of 4 different steroid regimens was done in 200 soldiers from July 2014 - July 2020. In the first group, oral Prednisolone 60 mg was administered for 6 days, in the second group for 8 days, in the third group for 10 days and in the fourth group for 12 days. Medication was tapered over the next 5 days in all the groups. Data analysed included demographics, Pure Tone Audiograms at admission and at 4 weeks, time of reporting to hospital, onset of treatment and type of treatment given. Multivariate linear regression model was done to consider the risk factors responsible for average hearing gain at all pure tones. Box-and-whisker plot, Mann-Whitney-Wilcoxon test, Kruskal Wallis test, Reciever Operating Characteristic curve were used to analyse the independent samples. p value of < 0.05 was considered statistically significant. Age, time of onset of prednisolone therapy and acoustic trauma due to blast or gunshot injury did not show correlation (R2 = 0.01, 0.01 and 0.35 respectively and p = 0.09, 0.71, 0.80 respectively). Prednisolone therapy, average initial hearing at pure tones were considered as factors responsible for hearing gain as they showed correlation (R2 = 0.22, and 0.34 respectively and p < 0.001 and < 0.01 respectively). Significant hearing gain was found in all groups. The hearing gain was statistically better in group 3 and 4 as compared to group 1 and 2. There was no statistically significant difference in hearing gain between groups 3 and 4. So there was no additional advantage of giving 60 mg oral prednisolone for more than 10 days. The best oral prednisolone regimen recommended is 60 mg/day for 10 days which is tapered over the next 5 days.

Effectiveness of hearing protection apparatus in preventing noise induced vestibular loss

Hearing protection apparatus (HPAs) are frequently used to prevent the detrimental effect of noise on the hearing system. However, it is not known exactly whether wearing HPAs in workers protects the vestibular system. This study aims to investigate the effectiveness of wearing HPAs in preventing vestibular loss caused by noise. Eighty-one workers exposed to chronic noise were divided into three groups according to their HPAs wearing status. Pure-tone audiometry test was used to evaluate the hearing. Caloric test and visual analogue scale were used to evaluate their vestibular systems. The pure-tone average of the workers who constantly wore HPAs was better than that of the other groups (p< 0.05). There was no difference between the groups in the vestibular tests (p > 0.05). This study demonstrated that HPAs do not protect the vestibular system but protect the hearing system in the inner ear from the harmful effects of noise.

Prevalence of hearing loss in children living in low- and middle-income countries over the last 10 years: A systematic review

AIM

To summarize the literature on the prevalence of pediatric hearing loss in low- and middle-income countries (LMICs).

METHOD

A systematic review initially identified 2833 studies, of which 122 met the criteria for inclusion. Eighty-six of those studies included diagnoses and were included in a meta-analysis.

RESULTS

The meta-analysis indicated a 1% (95% confidence interval = 0.8-2.0) prevalence of childhood hearing loss across LMICs. There was significant heterogeneity between studies and evidence of publication bias. The prevalence of mild and moderate cases of hearing loss was higher than more severe cases and there were fewer cases of mixed hearing loss compared to conductive or sensorineural hearing loss. No differences were identified between the prevalence of unilateral versus bilateral hearing loss or hearing loss according to sex. The quality of the studies, age of participants, and location of data collection may have influenced the results. High variability in the reporting of etiology made the causes of hearing loss unclear.

INTERPRETATION

The literature indicates that 1% of children in LMICs have hearing losses. However, most studies missed children with acquired hearing loss, which may lead to under-reporting of global prevalence. This systematic review is an initial step toward developing and implementing population-appropriate treatment and prevention programs for childhood hearing loss in LMICs.

Prevalence of Noise-Induced Tinnitus in Adults Aged 15 to 25 Years: A Cross-Sectional Study

Background Tinnitus is a common complaint in the general population. Subjective tinnitus is defined as a conscious perception of sound with nonexistent external stimuli. Its exact pathophysiology remains unclear. Therefore, this study aimed to determine the prevalence of noise-induced tinnitus among adults aged 15-25 years in Makkah, Saudi Arabia. Study design Convenience sampling was used for participant recruitment using an online survey that was distributed online between February and April 2022. The participants performed audiometric hearing tests provided by the investigators. Hearing tests were performed at frequencies of 250, 500, 1000, 2000, 4000, and 8000 Hz. The test was considered normal if the achieved thresholds were 25 dB HL or less in at least four of the tested frequencies. Those with normal results were asked to fill out a survey inquiring about their demographic information, presence of tinnitus, and tinnitus functional index. Results We included 119 young adults aged 15-25 years. Regarding tinnitus prevalence, 27 (22.7%) adults reported the development of tinnitus after exposure to loud noise, 39 (32.8%) had tinnitus of unknown cause, and 53 (44.5%) had no tinnitus. Regarding the continuity of sound, it was continuous in 14.8% of noise-induced tinnitus, compared to 38.5% of the other group, with a statistical significance of (P=.037). Conclusion The current study revealed high prevalence of tinnitus, which was also suggested by the literature. Several triggers are purportedly related to the development of tinnitus. Constant exposure to loud noise is considered a significant risk factor for tinnitus. Young adults require proper education about the causes of tinnitus and other hearing abnormalities. More importantly, methods to protect and maintain their ear health.

Local Delivery of Therapeutics to the Cochlea Using Nanoparticles and Other Biomaterials

Hearing loss negatively impacts the well-being of millions of people worldwide. Systemic delivery of ototherapeutics has limited efficacy due to severe systemic side effects and the presence of the blood-labyrinth barrier that selectively limits or enables transfer of molecules between plasma and inner ear tissues and fluids. Local drug delivery into the middle and inner ear would be preferable for many newly emerging classes of drugs. Although the cochlea is a challenging target for drug delivery, recent technologies could provide a safe and efficacious delivery of ototherapeutics. Local drug delivery routes include topical delivery via the external auditory meatus, retroauricular, transtympanic, and intracochlear delivery. Many new drug delivery systems specifically for the inner ear are under development or undergoing clinical studies. Future studies into these systems may provide a means for extended delivery of drugs to preserve or restore hearing in patients with hearing disorders. This review outlines the anatomy of the (inner) ear, describes the various local delivery systems and routes, and various quantification methodologies to determine the pharmacokinetics of the drugs in the inner ear.

Remote work: Aircraft noise implications, prediction, and management in the built environment

The COVID-19 pandemic has greatly changed workplace management. Most workplaces have adopted the work-from-home policy to minimize the risk of community spread. Consequently, housing estates remain largely occupied during office hours. Since some housing estates are situated in the vicinity of an airport, noise pollution resulted from the takeoff and landing of aircraft is now more noticed by residents, causing annoyance. This problem would be most acute for those located directly under the flight path. Before the pandemic, such aircraft operations had lower effect on the residents because most of them were not at home but at workplaces. Evidently, it is timely that more emphasis should now be placed during urban planning to predict and minimize aircraft noise in the built environment. This article first defines the aircraft noise metrics commonly used to assess environmental impact. Preceded by an overview of how aircraft noise affects the built environment, this article reviews how various aircraft noise prediction models have been used in urban planning. Lastly, this article reviews how aircraft noise can be managed for better acoustic comfort of the residents. Anticipating the adoption of hybrid work arrangement moving forward, this article aims to provide urban planning professionals with an avenue to understand how aircraft noise can negatively affect the built environment, which, in turn, justify why prediction and management of aircraft noise should be emphasized from the outset of urban planning.

Encouraging Hearing Loss Prevention in Music Listeners Using Personalized Technology: Questionnaire Study

Background

Noise-induced hearing loss (NIHL) affects millions of people despite being almost completely preventable. For recreational music listening through personal listening equipment (such as earbuds), it seems that listeners do not yet have a way to accurately assess their risk of developing hearing loss and prevent it accordingly.

Objective

The aim of this study is to analyze the perceived utility of a hypothetical device that encourages NIHL prevention based on listeners’ exposure to noise and to determine the most effective methods of such encouragement. Here, we describe 3 different potential NIHL risk notification method types, as follows: auditory, external visual, and visual.

Methods

An open, web-based survey was created on Google Forms, and the link was posted to Amazon’s Mechanical Turk as well as music-related Reddit communities. The survey was designed to gauge each respondent’s self-assessed NIHL awareness, willingness to lower their audio if reminded, and NIHL risk notification type preference. The likelihood of a specific notification type to encourage NIHL prevention among its users was based on the average of each user’s responses to 2 survey questions. Data collection started on July 13, 2020, and ended on July 17, 2020.

Results

Of the 116 respondents, 92 (79.3%) reported having prior awareness about NIHL; however, 60 (51.7%) described doing nothing to prevent it despite 96 (82.8%) feeling a moderate, high, or extreme risk of developing NIHL. Of those who already prevented NIHL, 96% (53.5/56) described using estimates to guide their prevention instead of using data. A Kruskal-Wallis test corrected for ties showed that despite the visual NIHL risk notification type being selected by the highest number of participants (84/116, 72.4%), the auditory type had a significantly higher (H1=6.848; P=.03) average percentage likelihood of encouraging NIHL prevention (62%, SD 24%) among the 40 respondents who chose it, with a median likelihood of 56% (95% CI 50%-75%). The visual type’s average likelihood was 50% (SD 28.1%), with a median of 50% (95% CI 37.5%-56.3%). Regardless of the NIHL risk notification type, 69% (80/116) of respondents were not opposed to using NIHL risk notifications and lowering their audio volume accordingly.

Conclusions

The hypothetical device detailed here was thought to be useful because most respondents (82.8%, 96/116) felt an extreme to moderate risk of developing NIHL and such a device could provide accurate data to those who currently use estimates to prevent NIHL, and most respondents were willing to act on NIHL risk notifications. The most effective NIHL risk notification type seemed to be the auditory type, but many aspects of this study need further research to determine which implementation method should reach the public.

Potential Effects on Human Safety and Health from Infrasound and Audible Frequencies Generated by Vibrations of Diesel Engines Using Biofuel Blends at the Workplaces of Sustainable Engineering Systems

Employees involved in various occupational environments that include vibration machines and any kind of vehicles are adversely subjected to multiple source noise. Thus, the corresponding noise frequencies (and mainly the infrasound ones) present high interest, especially from the viewpoint of sustainability, due to the potential effects on human safety and health (H_S&H) in sustainable engineering projects. Moreover, the occupational safety and health (OSH) visualization (a fact of unveiling the social dimension of sustainability) of occupational workplaces (by evaluating the infrasound and audible noise frequencies generated by diesel engines) could help a safety officer to lessen crucial risk factors in the OSH field and also to protect, more efficiently, the employees by taking the most essential safety measures. This study (i) suggests a technique to determine the infrasound and audible sound frequencies produced due to vibrations of diesel engines, by using biofuels (i.e., sustainable utilization of resources), in order to evaluate potential effects on human safety and health at the workplaces of sustainable engineering projects, and (ii) it ultimately aims to contribute to the improvement of the three “sustainability pillars” (economy, social, and environmental). Therefore, it provides experimental results of the frequency of the noise (regarding the infrasound and audible spectrum) that a diesel motor generates by vibration, in the frame of using different engine rpms (850, 1150, and 2000) and a variety of biofuel mixtures (B20-D80, B40-D60, B60-D40, and B80-D20). The article shows that the fuel blend meaningfully affects the generated noise, and more particularly, the usage of biofuel blends coming from mixing diesel oil with biodiesel (a fact of the emerging environmental dimension of sustainability) can produce various noise frequencies, which are determined in the infrasound and audible spectra (~10–23 Hz). The suggested technique, by ameliorating the OSH situation, doubtless will help enterprises to achieve the finest allocation of limited financial resources (a fact corresponding to the economic dimension of sustainability), allowing financial managers to have more available budget for implementing other risk-reduction projects.

Inner Ear Drug Delivery for Sensorineural Hearing Loss: Current Challenges and Opportunities

Most therapies for treating sensorineural hearing loss are challenged by the delivery across multiple tissue barriers to the hard-to-access anatomical location of the inner ear. In this review, we will provide a recent update on various pharmacotherapy, gene therapy, and cell therapy approaches used in clinical and preclinical studies for the treatment of sensorineural hearing loss and approaches taken to overcome the drug delivery barriers in the ear. Small-molecule drugs for pharmacotherapy can be delivered via systemic or local delivery, where the blood-labyrinth barrier hinders the former and tissue barriers including the tympanic membrane, the round window membrane, and/or the oval window hinder the latter. Meanwhile, gene and cell therapies often require targeted delivery to the cochlea, which is currently achieved via intra-cochlear or intra-labyrinthine injection. To improve the stability of the biomacromolecules during treatment, e.g., RNAs, DNAs, proteins, additional packing vehicles are often required. To address the diverse range of biological barriers involved in inner ear drug delivery, each class of therapy and the intended therapeutic cargoes will be discussed in this review, in the context of delivery routes commonly used, delivery vehicles if required (e.g., viral and non-viral nanocarriers), and other strategies to improve drug permeation and sustained release (e.g., hydrogel, nanocarriers, permeation enhancers, and microfluidic systems). Overall, this review aims to capture the important advancements and key steps in the development of inner ear therapies and delivery strategies over the past two decades for the treatment and prophylaxis of sensorineural hearing loss.

Subclinical Atherosclerosis Could Increase the Risk of Hearing Impairment in Males: A Community-Based Cross-Sectional Survey of the Kailuan Study

Objective

The relationship between subclinical atherosclerosis and hearing impairment (HI) has not been widely considered. Brachial ankle pulse wave velocity (baPWV) is a good indicator of muscular artery elasticity and could be a feasible method to screen for subclinical atherosclerosis. Our study aimed to elucidate the relationship between baPWV and HI.

Methods

This cross-sectional study was based on the Kailuan cohort. All participants completed a standardized questionnaire and underwent physical examinations and laboratory assessments at recruitment. Since 2010, some participants received additional baPWV testing during follow-up visits, and some who were exposed to occupational hazards such as noise received a pure-tone average hearing threshold (PTA) test after 2014. Male subjects with a complete physical examination, baPWV, and PTA data were recruited for this study. HI was defined as PTA > 25 dB. Multivariate linear and multivariate logistic regression analyses were used to evaluate the relationship between baPWV and PTA or HI.

Results

Among 11,141 subjects, the age range was 18–65 years, with mean age of 43.3 ± 8.9 years, the average PTA was 20.54 ± 10.40 dB, and the detection rate of HI was 1,821/11,141 (16.3%). Subjects were divided into four subgroups according to baPWV quartile. As the baPWV quartile increased, age, systolic blood pressure, diastolic blood pressure, body mass index, total cholesterol, high-density-lipoprotein cholesterol, fasting blood glucose, PTA, and proportions of subjects reporting smoking, alcohol consumption, hypertension, and diabetes increased significantly (p < 0.05 for trend). The odds of HI were higher in the fourth quartile group [adjusted odds ratio (aOR): 1.33, 95% CI: 1.10–1.62] than in the first quartile group. For every 100 m/s increase in baPWV, the PTA increased by 13 dB (95% CI: 4–23). When we divided the subjects into young (5,478 subjects; age range 22–44 years; mean age 35.6 ± 5.5 years) or non-young subgroups (5,663 subjects; age range 45–65 years; mean age 50.7 ± 3.7 years) based on a cut-off age of 45 years, the aOR of the fourth quartile group increased to 2.65 (95% CI: 1.68–4.19), and the PTA increment increased to 18 dB (95% CI: 10–27) for every 100 m/s increase in baPWV in the young subgroup. However, this relationship became statistically insignificant in the non-young subgroup.

Conclusion

Our study revealed the quantitative relationship between baPWV and HI in the Kailuan cohort subjects, although the results are not universally consistent in different populations.

Are Smartwatches a Suitable Tool to Monitor Noise Exposure for Public Health Awareness and Otoprotection?

Introduction and Objectives

Noise-induced hearing loss (NIHL) and tinnitus are common problems that can be prevented with hearing protection measures. Sound level meters and noise dosimeters enable to monitor and identify health-threatening occupational or recreational noise, but are limited in their daily application because they are usually difficult to operate, bulky, and expensive. Smartwatches, which are becoming increasingly available and popular, could be a valuable alternative to professional systems. Therefore, the aim of this study was to evaluate the applicability of smartwatches for accurate environmental noise monitoring.

Methods

The A-weighted equivalent continuous sound pressure level (L_Aeq) was recorded and compared between a professional sound level meter and a popular smartwatch. Noise exposure was assessed in 13 occupational and recreational settings, covering a large range of sound pressure levels between 35 and 110 dBA. To assess measurement agreement, a Bland-Altman plot, linear regression, the intra-class correlation coefficient, and descriptive statistics were used.

Results

Overall, the smartwatch underestimated the sound level meter measurements by 0.5 dBA (95% confidence interval [0.2, 0.8]). The intra-class correlation coefficient showed excellent agreement between the two devices (ICC = 0.99), ranging from 0.65 (music club) to 0.99 (concert) across settings. The smartwatch's sampling rate decreased significantly with lower sound pressure levels, which could have introduced measurement inaccuracies in dynamic acoustic environments.

Conclusions

The assessment of ambient noise with the tested smartwatch is sufficiently accurate and reliable to improve awareness of hazardous noise levels in the personal environment and to conduct exploratory clinical research. For professional and legally binding measurements, we recommend specialized sound level meters or noise dosimeters. In the future, smartwatches will play an important role in monitoring personal noise exposure and will provide a widely available and cost-effective measure for otoprotection.

Self Reported Hearing Impairments and Associated Risk Factors Among Metal and Woodwork Workers in Gondar Town, North West Ethiopia

BACKGROUND

The global prevalence of occupational noise-induced hearing loss ranges between 16% and 24%. The wood and metalwork industries have recently expanded in Ethiopia. This study aims to determine the level of noise exposure and the prevalence of self-reported hearing impairments and associated risk factors among metal and woodworkers in Gondar town Ethiopia.

MATERIAL AND METHODS

An institutional-based cross-sectional study was conducted on 580 metal and woodwork workers from February10 to March 25/2020. The data were collected through an interviewer-led questioner and the noise level measurement. Multivariate Poisson regression models were used. P-values less than .05 and adjusted prevalence ratios with 95%CI were used to declare the presence and strength of an association respectively.

RESULT

The mean (SD) average noise exposure level in the wood and metalworking industries was 96.9 ± 3.5 dBA and 96.2 ± 4 dBA, respectively. The overall prevalence of self-reported hearing impairment was 20.7% [95%CI: (17.4-24)]. In an adjusted Poisson regression, listening to music with earphones for more than 2 hours per day (PR = 2.95, 95%CI: 1.32, 6.21) and listening to music at maximum volume (PR = 2.24, 95%CI: 1.05, 4.79) were associated with hearing impairments.

CONCLUSION

The majority of workers are exposed to noise levels that exceed OSHA's permissible exposure limit value. A hearing conservation program should be implemented to reduce noise exposure levels in the wood and metal work industries. Workers should be aware of the duration and volume of recreational noise exposure.

Influence of noise level and seniority in the workplace on the SAL, ELI and percentage of hearing loss indices in the diagnosis and prevention of hearing loss in the working population

INTRODUCTION

This research relates the most important work-related factors affecting the development of hearing loss to the main methods used as medical assessment criteria in the diagnosis of occupational deafness. These criteria are the Speech Average Loss Index (SAL), the Early Loss Index (ELI) and the Percentage of Hearing Loss, and are applied to data obtained from audiograms performed on workers in occupational medical examinations.

METHOD

Depending on the assessment method selected, these often return different results in grading an individual's hearing status and predicting how it will evolve. To address this problem, medical examinations (including audiograms) were carried out on a heterogeneous sample of 1,418 workers in Spain, from which demographic or personal data (gender, age, etc.), occupational data (noise level to which each individual is exposed, etc.) and other non-work-related factors (exposure to noise outside work, family history, etc.) were also gathered. Using Bayesian Networks, the conditional probability of an individual developing hearing loss was obtained taking into account all these factors and, specifically, noise level and length of service in the workplace. Sensitivity analyses were also carried out using the three scales (SAL, ELI and Percentage Hearing Loss Index), proving their suitability as tools the diagnosis and prediction of deafness. These networks were validated under the Receiver Operating Characteristic curve (ROC) criterion and in particular by the Area Under the Curve (AUC).

RESULTS

The results show that all three methods are deficient in so far as detecting preventive hearing problems related to noise in most workplaces.

CONCLUSIONS

The most restrictive methods for detecting possible cases of deafness are the SAL index and the Percentage Loss Index. The ELI index is the least restrictive of the three methods, but it is not able to discriminate the causes of hearing problems in an individual caused by exposure to noise, either by its intensity level or by the time of exposure to noise. Practical Applications: The use of the three methods in the field of occupational risk prevention is extremely limited and it seems reasonable to think that there is a need for the construction of new scales to correct or improve the existing ones.

A Comparison of Self-Reported Nonoccupational Noise Exposure in a Large Cohort of Listeners

Objective

A variety of questionnaires have been developed to describe and quantify occupational and nonoccupational noise exposure, which are associated with hearing loss and tinnitus. The main aim of this study was to compare and contrast three commonly used nonoccupational noise exposure measurement questionnaires in a group of young adults.

Materials and Methods

A total of 197 participants were recruited for this study. All the participants completed three commonly used nonoccupational noise exposure measurement questionnaires via Qualtrics software (Qualtrics, Provo, UT). General patterns in the nature of noise exposure were highlighted and statistical agreement and correlations between the three instruments were calculated. Comparisons were made between self-percept of noise exposure and annual noise exposure metrics obtained using questionnaires.

Results

Strong statistical agreement and correlation (r = 0.57, P < 0.001) was found between the selected instruments similar in their constructs of noise exposure. When compared to quantified scores of noise exposure, self-report of exposure to loud noise was highly sensitive but associated with poor specificity (3.61%) and a high false-positive rate (96.38%). The majority of participants reported exposure to noise from listening to music and attending loud recreational activities, with a differential effect of sex on average annual noise exposure values depending on the questionnaire used.

Conclusions

The outcomes of this analysis could assist in comparing noise exposure quantifications across research studies, and determining if and how these questionnaires may be utilized clinically to effectively identify and counsel those at risk for noise-induced hearing loss.