Hearing Difficulties Among Farmworkers in the México-US Southwest Border Region

Migrant and seasonal farmworkers are a vulnerable population with a potentially high risk for hearing loss due to farm-related noise exposures. Occupational noise-induced hearing loss (NIHL) is permanent, and it is associated with an increased risk for injuries on the job, as well as communication difficulties, isolation, and depression. The México/US border region is one of the most productive agricultural regions in the country, however, no known studies have explored hearing loss among farmworkers in this area. This pilot study was a first step toward measuring and addressing hearing loss and noise exposure among this region's farmworkers. We conducted a cross-sectional survey to estimate the prevalence of subjective hearing difficulties among Yuma County, Arizona farmworkers. Survey interviews took place during a late-night farmworker health fair from 2 am to 6 am to accommodate local farms' labor schedules. Multivariable regression adjusted for demographic and work covariates estimated subjective hearing loss prevalence ratios. Among 132 farmworker participants, 36% reported they have or might have hearing loss, and 62% reported no hearing loss. Subjective hearing loss prevalence was lower in farmworkers who report not working in noise compared to prevalence in farmworkers who work in noise [prevalence ratio, 0.44 (95% CI 0.23-0.82)]. This report contributes to understanding the perception of hearing-related health and occupational exposures among farmworkers in the México-US Southwest border region. The information from this line of research will inform appropriate safety measures known to lower the risk of experiencing occupational NIHL.

ERK1/2 Inhibition Alleviates Noise-Induced Hearing Loss While Tempering Down the Immune Response

Noise-induced hearing loss (NIHL) is a major cause of hearing impairment, yet no FDA-approved drugs exist to prevent it. Targeting the mitogen activated protein kinase (MAPK) cellular pathway has emerged as a promising approach to attenuate NIHL. Tizaterkib is an orally bioavailable, highly specific ERK1/2 inhibitor, currently in Phase-1 anticancer clinical trials. Here, we tested tizaterkib's efficacy against permanent NIHL in mice at doses equivalent to what humans are currently prescribed in clinical trials. The drug given orally 24 hours after noise exposure, protected an average of 20-25 dB SPL in three frequencies, in female and male mice, had a therapeutic window >50, and did not confer additional protection to KSR1 genetic knockout mice, showing the drug works through the MAPK pathway. Tizaterkib shielded from noise-induced cochlear synaptopathy, and a 3-day, twice daily, treatment with the drug was the optimal determined regimen. Importantly, tizaterkib was shown to decrease the number of CD45 and CD68 positive immune cells in the cochlea following noise exposure, which could be part of the protective mechanism of MAPK inhibition.

P2X7 receptor is required for the ototoxicity caused by aminoglycoside in developing cochlear hair cells

Aminoglycoside antibiotics (AGAs) are widely used in life-threatening infections, but they accumulate in cochlear hair cells (HCs) and result in hearing loss. Increases in adenosine triphosphate (ATP) concentrations and P2X7 receptor expression were observed after neomycin treatment. Here, we demonstrated that P2X7 receptor, which is a non-selective cation channel that is activated by high ATP concentrations, may participate in the process through which AGAs enter hair cells. Using transgenic knockout mice, we found that P2X7 receptor deficiency protects HCs against neomycin-induced injury in vitro and in vivo. Subsequently, we used fluorescent gentamicin-Fluor 594 to study the uptake of AGAs and found fluorescence labeling in wild-type mice but not in P2rx7-/- mice in vitro. In addition, knocking-out P2rx7 did not significantly alter the HC count and auditory signal transduction, but it did inhibit mitochondria-dependent oxidative stress and apoptosis in the cochlea after neomycin exposure. We thus conclude that the P2X7 receptor may be linked to the entry of AGAs into HCs and is likely to be a therapeutic target for auditory HC protection.

Effect of acoustic noise reduction technology on image quality: a multivendor study

The purpose of this study was to clarify the appropriate use of a combination of pulse sequences and acoustic noise reduction technology in general-purpose brain magnetic resonance imaging. Five pulse sequences commonly used in brain magnetic resonance imaging examinations-turbo spin-echo T2-weighted imaging, T1-weighted fluid-attenuated inversion recovery, T2-weighted fluid-attenuated inversion recovery, diffusion-weighted imaging, and magnetic resonance angiography-were performed on healthy participants at three vendors where acoustic noise reduction technology was available. The results showed that acoustic noise reduction technology reduced sound pressure levels and altered image quality in all pulse sequences across all vendors' magnetic resonance imaging scanners. Although T2-weighted imaging and T1-weighted fluid-attenuated inversion recovery resulted in little image quality degradation, T2-weighted fluid-attenuated inversion recovery, diffusion-weighted imaging, and magnetic resonance angiography had significant image degradation. Therefore, acoustic noise reduction technology should be used with caution.

[The professional ear user-implications for the prevention, diagnosis, and treatment of ear diseases]

BACKGROUND

Perfect hearing is crucial to the practice of various professions, such as instrument makers, musicians, sound engineers, and other professions not related to music, such as sonar technicians. For people of these occupational groups, we propose the term "professional ear user" (PEU) in analogy to "professional voice user". PEUs have special requirements for their hearing health, as they have well-known above-average auditory perceptual abilities on which they are professionally dependent.

OBJECTIVE

The purpose of this narrative review is to summarize selected aspects of the prevention, diagnosis, and treatment of ear disorders in PEUs.

RESULTS AND CONCLUSION

Prevention of hearing disorders and other ear diseases includes protection from excessive sound levels, avoidance of ototoxins and nicotine, and a safe manner of cleaning the outer auditory canal. Diagnosing hearing disorders in PEUs can be challenging, since subclinical but relevant changes in hearing cannot be reliably objectified by conventional audiometric methods. Moreover, the fact that a PEU is affected by an ear disease may influence treatment decisions. Further, physicians must be vigilant for non-organic ear diseases in PEUs. Lastly, measures to promote comprehensive ear health in PEUs as part of an educational program and to maintain ear health by means of a specialized otolaryngology service are discussed. In contrast to existing concepts, we lay the attention on the entirety of occupational groups that are specifically dependent on their ear health in a professional setting. In this context, we suggest avoiding a sole focus on hearing disorders and their prevention, but rather encourage the maintenance of a comprehensive ear health.

The contribution of respiratory and hearing protection use to psychological distress in the workplace: a scoping review

OBJECTIVE

Workers from various industries use personal protective equipment (PPE) including masks, respirators, and hearing protection to reduce their exposures to workplace hazards. Many studies have evaluated the physiological impacts of PPE use, but few have assessed the psychological impacts. The aim of the present study was to carry out a scoping review to compile existing evidence and determine the extent of knowledge on workplace mask, respirator or hearing protection use as a psychosocial hazard (stressor) that could result in a stress response and potentially lead to psychological injury.

METHODS

The scoping review followed recognized methods and was conducted using Ovid Emcare, PubMed, Sage Journals, ScienceDirect, Scopus, SpringerLink, Google Scholar and preprint databases (OSF Preprints and medRxiv). Articles on the stressors associated with the use of masks, respirators, and hearing protection were included. The extracted data included author(s) name, year of publication, title of article, study design, population data, stressors assessed, and key findings.

RESULTS

We retrieved 650 articles after removal of duplicates, of which 26 were deemed eligible for inclusion for review. Identified factors associated with PPE use that could potentially create a stress response were identified: communication impacts, physical impacts, psychological illness symptoms, cognitive impacts, and perceived PPE-related impacts. Evidence for respirators suggest that there may be psychological injury associated with their use. However, hearing protection appears to have a protective effect in reducing psychological symptoms such as anxiety, depression, and aggression.

CONCLUSIONS

Mask or respirator use may lead to an increase in work-related stress. Whereas hearing protection may have protective effects against psychological symptoms and improves speech intelligibility. More research is needed to better understand potential psychosocial impacts of mask, respirator and/or hearing protection use.

A Test of Social Cognitive Theory to Increase Hearing Protection Use in Swine Buildings

Farming ranks among the top occupations for which workers are at risk for noise-induced hearing loss (NIHL), an irreversible yet preventable condition. Hearing Protection Devices (HPDs) (i.e., earmuffs and ear plugs) are effective at preventing expo- sure to noise; however, few farmers report consistent use. The purpose of this study was to test an intervention based on Social Cognitive Theory with interactive smartphone technology to increase the use of HPDs among swine facility workers. A pilot, quasi-experimental study was implemented among 72 younger adult swine workers. Participants were randomly assigned to one of three groups. Group 1 received HPDs (e.g., earmuffs and ear plugs). Group 2 received the same HPDs as Group 1 and was also instructed to use a smartphone application to track their use of hearing protection for 60 days. Group 3 received the HPDs and instructions on using a smartphone app for tracking the use of hearing protection and setting daily goals for hearing protection use. Use of hearing protection was assessed via an online survey prior to the intervention (i.e., "baseline"), immediately after the post-intervention, and at a 3-month follow-up. Compared to baseline use, all three groups reported increased use of hearing protection immediately post-intervention. However, this increase was not maintained at a 3-month follow-up for two of the study groups. Group 3 (HPD, tracking, and goal-setting app) showed the greatest increase in the use of HPDs from baseline to immediate post-intervention; however, Group 1 (HPD only) showed the greatest sustained increase from baseline to the 3-month follow-up. Modifying the environment by supplying HPDs was effective in increasing HPD use among swine facility workers. Improving access to hearing protection devices alone may lead to sustained changes in behavior.

The effect of wearing an anti-flash hood on the noise attenuation of earmuffs

The insertion losses of four pairs of earmuffs, including one noise-excluding headset, were measured in one-third octave bands in a diffuse broadband noise field using a head-like acoustic test fixture. The acoustic test fixture contained realistic ear simulators with microphones at the eardrum positions. The insertion losses were measured (i) with the earmuffs on their own, (ii) with the earmuffs worn over an anti-flash hood, and (iii) for one earmuff, with the earmuff worn under the hood. The other three earmuffs could not be fitted under the hood. The insertion loss of the anti-flash hood on its own was also measured. Wearing an anti-flash hood under the earmuffs greatly reduced the protection against noise, by 20-23 dB at high frequencies, by 17-20 dB at middle frequencies, by 12-16 dB at low frequencies, and by 16-20 dB overall. Only one earmuff was slim enough to fit under an anti-flash hood. Wearing an anti-flash hood over this earmuff had only a marginal effect on the earmuff insertion loss, of the order of 1 dB. If anti-flash hoods could be designed to fit over other types of earmuffs and headsets, the protection of these earmuffs and headsets would be virtually maintained.

Acoustic-Perceptual Correlates of Voice Among Steam Train Engineers: Effects of Noise and Hearing Protection

Occupational voice users are at a higher risk for developing voice disorders due to their vocal demands, such as prolonged periods of work-related voice use and nonideal environmental factors, such as speaking above background noise. The current study focused on the effects of background noise and hearing protection on acoustic-perceptual correlates of voice among steam train engineers. Fourteen participants phonated vowel /a/, read a phrase, and described a map under different noise and hearing protection conditions. Relative sound pressure level, relative fundamental frequency, and perceived vocal effort and disturbance decreased in the presence of hearing protection for all noise conditions. In contrast, these acoustic measures increased in the absence of hearing protection supporting Lombard effect. Overall, results of the current study provide insight into possible risks to vocal health in workers exposed to high levels of background noise and use hearing protection.

Epidemiology of the extent of recreational noise exposure and hearing protection use: cross-sectional survey in a nationally representative UK adult population sample

Background

Hearing loss is prevalent and disabling, yet little is known about the extent of recreational noise exposure and hearing protection use. The aim of the present research was to estimate the extent of recreational noise exposure and hearing protection use in a sample representative of the UK adult population.

Methods

We conducted a cross-sectional survey of 10,401 UK adults who were representative of the population.

Results

More than 7000 people (n = 7590, 73.0%) reported exposure to recreational noise excluding headphone and earphone use in the last 12 months. Just 158 people (2.1%) reported wearing hearing protection for every noisy recreational activity. Age (younger people) and beliefs of a behavioral (as opposed to genetic) cause of hearing loss were predictive of both higher recreational noise exposure and greater hearing protection use. Men were more exposed to recreational noise but women were less likely to use hearing protection.

Conclusions

For the first time, the present research quantifies the recreational noise exposure and low levels of hearing protection use in a representative sample of the UK population. The biggest public health gains are likely to be achieved through interventions targeted at younger people and in explaining behavioral (as opposed to genetic) causes of hearing loss.

Children who say hand dryers 'hurt my ears' are correct: A real-world study examining the loudness of automated hand dryers in public places

Introduction

Previous research has suggested that hand dryers may operate at dangerously loud levels for adults. No research has explored whether they operate at a safe level for children's hearing. Children's ears are more sensitive to damage from loud sounds than adult ears. Health Canada prohibits the sale of toys with peak loudness greater than 100 dB. This study tested installed dryers in public washrooms to see if they were safe for children's hearing.

Methods

Forty-four hand dryers in public washrooms were each measured for peak sound levels in a standardized fashion, including at children's ear canal heights. Each dryer was measured at 10 different combinations of heights and distances from the wall, and with and without hands in the air stream coming from the hand dryer, for a total of 20 measurements per dryer.

Results

Xlerator units performed the loudest, with all being louder than 100 dBA at all measurements whenever hands were in the airstream. Several Dyson Airblade models were also very loud, including the single loudest measurement of 121 dBA. While some other units operated at low sound levels, many units were louder at children's ear heights than at adult ear heights.

Discussion

Many dryers operated much louder than their manufacturers claimed, usually greater than 100 dBA (the maximum allowable noise level for products/toys meant for children).

Conclusion

This study suggests that many hand dryers operate at levels far louder than their manufacturers claim and at levels that are clearly dangerous to children's hearing.

[The hearing self-protection behavior and internal factors of workers exposured to occupational noise]

Objective: To analyze the hearing self-protection behavior patterns and internal factors of workers exposured to occupational noise in an aircraft manufacturing industry based on health belief model, so as to provide reference for further health promotion programs and intervention measures. Methods: A total of 1600 front-line workers were selected from 10 units of an aircraft manufacturing enterprise by cluster sampling method. The basic and occupational information of employees were collected, and a self-reported questionnaire was designed according to the health belief model to acquire the hearing self-protection behaviors of workers. Results: There were significant differences in the perceived severity, perceived benefit, perceived impairment, self-efficacy and behavioral incentive scores of different hearing self-protection behaviors among the noise-causing workers (P<0.05). There were significant differences in the distribution of hearing self-protection behaviors among different genders, ages, education levels, length of service, initial noise exposure time and cumulative noise reception time (P<0.05). The perceived benefits, perceived barriers, behavioral incentives, self-efficacy scores, and educational attainment of the noise-causing workers were all related to the type of hearing self-protection behavior (P<0.05) . Conclusion: The educational level and health belief model can predict the hearing self-protection behavior patterns of front-line workers to some extent, more attention should be paid to the monitoring of the well-educated employees.

[Comparison of knowledge and behavior toward hearing protection among workers in different workplaces and its influence factors]

Objective: To compare the knowledge and behavior toward hearing protection among workers in different workplaces and investigate its influence factors. Methods: 2 manufacturing companies with obvious noise hazard in workplace were selected into the study. Health management level was distinguished through field investigation and verification. Questionnaire focus on basic knowledge of hearing health, acceptance level of noise hazard, comfort of wearing hearing protectors and atmosphere in workplace was designed and was used to investigate the knowledge and behavior toward hearing protection. Results: Hearing protectors that meet the level of protection are distributed throughout the workplaces. Although company A has a lower noise hazards level, the health management system was poorly executed. The proportion of workers persisting in wearing hearing protectors throughout the work shift in company A was lower than B (P<0.01) . Workers in company A intended to underestimate the noise level (P<0.01) and the health effect of hearing loss (P<0.01) . All the workers were worry about suffering from hearing loss (P>0.05) , but those in company B had more positive attitude toward the protection of hearing protector (P<0.01) and relied on the protector (P<0.01) . The awareness of protection, in turn, help workers adapt attitude and get used to wearing hearing protectors consciously in workplace (P<0.01) . Conclusion: Health management performance play a key role in help workers form good knowledge and behavior. To protect workplace health, employers need to creative a healthy supportive environment for workers.

Altai pika (Ochotona alpina) alarm calls: individual acoustic variation and the phenomenon of call-synchronous ear folding behavior

Non-hibernating pikas collect winter food reserves and store them in hay piles. Individualization of alarm calls might allow discrimination between colony members and conspecifics trying to steal food items from a colony pile. We investigated vocal posture, vocal tract length, and individual acoustic variation of alarm calls, emitted by wild-living Altai pikas Ochotona alpina toward a researcher. Recording started when a pika started calling and lasted as long as possible. The alarm call series of 442 individual callers from different colonies consisted of discrete short (0.073-0.157 s), high-frequency (7.31-15.46 kHz), and frequency-modulated calls separated by irregular intervals. Analysis of 442 discrete calls, the second of each series, revealed that 44.34% calls lacked nonlinear phenomena, in 7.02% nonlinear phenomena covered less than half of call duration, and in 48.64% nonlinear phenomena covered more than half of call duration. Peak frequencies varied among individuals but always fitted one of three maxima corresponding to the vocal tract resonance frequencies (formants) calculated for an estimated 45-mm oral vocal tract. Discriminant analysis using variables of 8 calls per series of 36 different callers, each from a different colony, correctly assigned over 90% of the calls to individuals. Consequently, Altai pika alarm calls are individualistic and nonlinear phenomena might further increase this acoustic individualization. Additionally, video analysis revealed a call-synchronous, very fast (0.13-0.23 s) folding, depression, and subsequent re-expansion of the pinna confirming an earlier report of this behavior that apparently contributes to protecting the hearing apparatus from damage by the self-generated high-intensity alarm calls.

Spectral analysis of hearing protector impulsive insertion loss

OBJECTIVE

To characterise the performance of hearing protection devices (HPDs) in impulsive-noise conditions and to compare various protection metrics between impulsive and steady-state noise sources with different characteristics.

DESIGN

HPDs were measured per the impulsive test methods of ANSI/ASA S12.42- 2010 . Protectors were measured with impulses generated by both an acoustic shock tube and an AR-15 rifle. The measured data were analysed for impulse peak insertion loss (IPIL) and impulsive spectral insertion loss (ISIL). These impulsive measurements were compared to insertion loss measured with steady-state noise and with real-ear attenuation at threshold (REAT).

STUDY SAMPLE

Tested HPDs included a foam earplug, a level-dependent earplug and an electronic sound-restoration earmuff.

RESULTS

IPIL for a given protector varied between measurements with the two impulse noise sources, but ISIL agreed between the two sources. The level-dependent earplug demonstrated level-dependent effects both in IPIL and ISIL. Steady-state insertion loss and REAT measurements tended to provide a conservative estimate of the impulsively-measured attenuation.

CONCLUSIONS

Measurements of IPIL depend strongly on the source used to measure them, especially for HPDs with less attenuation at low frequencies. ISIL provides an alternative measurement of impulse protection and appears to be a more complete description of an HPD's performance.

Hearing Sensation Changes When a Warning Predicts a Loud Sound in the False Killer Whale (Pseudorca crassidens)

Stranded whales and dolphins have sometimes been associated with loud anthropogenic sounds. Echolocating whales produce very loud sounds themselves and have developed the ability to protect their hearing from their own signals. A false killer whale's hearing sensitivity was measured when a faint warning sound was given just before the presentation of an increase in intensity to 170 dB. If the warning occurred within 1-9 s, as opposed to 20-40 s, the whale showed a 13-dB reduction in hearing sensitivity. Warning sounds before loud pulses may help mitigate the effects of loud anthropogenic sounds on wild animals.

Effectiveness of a preventive campaign for noise-induced hearing damage in adolescents

OBJECTIVES

Many studies have documented a high incidence of hearing loss and tinnitus in adolescents after recreational noise exposure. The prevalence of noise-induced symptoms is in contradiction to the low preventive use of hearing protection. The effects of preventive campaigns on the attitudes toward noise in young people are under debate. The aim of the present study is to investigate whether a preventive campaign can alter attitudes toward noise in adolescents and whether this results in an increase of hearing protection use in this population.

METHODS

A cohort of 547 Flemish high school students, aged 14 to 18 years old, completed a questionnaire prior to and after a governmental campaign focusing on the harmful effects of recreational noise and the preventive use of hearing protection. At both occasions the attitudes toward noise and toward hearing protection were assessed by use of the youth attitudes toward noise scale (YANS) and the beliefs about hearing protection and hearing loss (BAHPHL), respectively. These questionnaires fit into the model of the theory of planned behavior which provides a more clear insight into the prediction of a certain behavior and the factors influencing that behavior.

RESULTS

The score on the YANS and the BAHPHL decreased significantly (p < 0.001) implying a more negative attitude toward noise and a more positive attitude toward hearing protection. The use of hearing protection increased significantly from 3.6% prior to the campaign to 14.3% (p = 0.001) post campaign in students familiar with the campaign.

CONCLUSIONS

Measurable alteration of all the variables in the theory of planned behavior caused an increase of the intentions to use hearing protection as well as the actual use of hearing protection. The present study shows the usefulness of the theory of planned behavior to change and guide adolescents' preventive actions toward noise damage. In addition, preventive campaigns can establish attitude and behavioral adjustments. However, the long term effects of preventive campaigns should be investigated in future research.

The effect of alpha-lipoic acid on temporary threshold shift in humans: a preliminary study

Noise-induced hearing loss (NHIL) is a significant source of hearing loss in industrialized countries. Recent research on the cellular bases of NIHL has led to new avenues for protection through prophylactic drugs. Although in experimental animal models several compounds have shown a protective effect in NIHL, limited data are available in humans. Many authors are focusing their attention on the role of antioxidant on hearing protection. Alpha-lipoic acid (ALA), an essential cofactor in mitochondrial enzymes, is a novel biological antioxidant and a potent free radical scavenger and, in animal models, it has been shown to protect from age-induced and cisplatin-induced hearing loss. The aim of our study was to evaluate the effect of alpha-lipoic acid on temporary threshold shift measured 2 minutes after the end of exposure (TTS(2)) induced by a 3 kHz tone in young normally hearing subjects. Thirty young normal hearing volunteers served as control subjects. Individuals were randomly assigned to three groups. Group A (10 subjects) subjects were exposed to a 90 dB HL 3 kHz pure tone for 10 min. Group B (10 subjects) subjects were exposed to a 90 dB HL 3 kHz pure tone one hour after oral ingestion of 600 mg of ALA. Group C (10 subjects) were exposed to a 90 dB HL 3 kHz pure tone after 10 days of oral ingestion of 600 mg of ALA. Statistical analysis showed that prior to the exposure the hearing thresholds did not differ significantly among the three groups. TTS(2) of group C was significantly lower that TTS2 of Groups A and B at 6 kHz (p 0.03), and TEOAEs amplitude change after noise exposure was lower for group C compared to Groups A (p = 0.089) and B (p = 0.03). ALA is a powerful lipophilic antioxidant and free radical scavenger currently used in clinical practice. A single dose of 600 mg of dose ALA did not induce any protection on the TTS(2) induced by a 90 dB HL 3 kHz tone, while 10 days of therapeutic dosage assumption of ALA was associated with significant protection at 6 kHz. The results of this study show that a short course of ALA protects from TTS(2) in humans, and therefore further studies are needed to better define the role of ALA in the prevention of noise induced hearing loss.