Hearing protection field attenuation estimation systems and associated training for reducing workers' exposure to noise.

BACKGROUND: Global Burden of Disease studies identify hearing loss as the third leading cause of years lived with a disability. Their estimates point to large societal and individual costs from unaddressed hearing difficulties. Workplace noise is an important modifiable risk factor; if addressed, it could significantly reduce the global burden of disease. In practice, providing hearing protection devices (HPDs) is the most common intervention to reduce noise exposure at work. However, lack of fit of HPDs, especially earplugs, can greatly limit their effectiveness. This may be the case for 40% of users. Testing the fit and providing instructions to improve noise attenuation might be effective. In the past two decades, hearing protection fit-test systems have been developed and evaluated in the field. They are called field attenuation estimation systems. They measure the noise attenuation obtained by individual workers using HPDs. If there is a lack of fit, instruction for better fit is provided, and may lead to better noise attenuation obtained by HPDs. OBJECTIVES: To assess: (1) the effects of field attenuation estimation systems and associated training on the noise attenuation obtained by HPDs compared to no instruction or to less instruction in workers exposed to noise; and (2) whether these interventions promote adherence to HPD use. SEARCH METHODS: We used CENTRAL, MEDLINE, five other databases, and two trial registers, together with reference checking, citation searching, and contact with study authors to identify studies. We imposed no language or date restrictions. The latest search date was February 2024. SELECTION CRITERIA: We included randomised controlled trials (RCTs), cluster-RCTs, controlled before-after studies (CBAs), and interrupted time-series studies (ITSs) exploring HPD fit testing in workers exposed to noise levels of more than 80 A-weighted decibels (or dBA) who use hearing protection devices. The unit 'dBA' reports on the use of a frequency-weighting filter to adjust sound measurement results to better reflect how human ears process sound. The outcome noise attenuation had to be measured either as a personal attenuation rating (PAR), PAR pass rate, or both. PAR pass rate is the percentage of workers who passed a pre-established level of sufficient attenuation from their HPDs, identified on the basis of their individual noise exposure. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed study eligibility, risk of bias, and extracted data. We categorised interventions as fit testing of HPDs with instructions at different levels (no instructions, simple instructions, and extensive instructions). MAIN RESULTS: We included three RCTs (756 participants). We did not find any studies that examined whether fit testing and training contributed to hearing protector use, nor any studies that examined whether age, gender, or HPD experience influenced attenuation. We would have included any adverse effects if mentioned by the trial authors, but none reported them. None of the included studies blinded participants; two studies blinded those who delivered the intervention. Effects of fit testing of HPDs with instructions (simple or extensive) versus fit testing of HPDs without instructions Testing the fit of foam and premoulded earplugs accompanied by simple instructions probably does not improve their noise attenuation in the short term after the test (1-month follow-up: mean difference (MD) 1.62 decibels (dB), 95% confidence interval (CI) -0.93 to 4.17; 1 study, 209 participants; 4-month follow-up: MD 0.40 dB, 95% CI -2.28 to 3.08; 1 study, 197 participants; both moderate-certainty evidence). The intervention probably does not improve noise attenuation in the long term (MD 0.15 dB, 95% CI -3.44 to 3.74; 1 study, 103 participants; moderate-certainty evidence). Fit testing of premoulded earplugs with extensive instructions on the fit of the earplugs may improve their noise attenuation at the immediate retest when compared to fit testing without instructions (MD 8.34 dB, 95% CI 7.32 to 9.36; 1 study, 100 participants; low-certainty evidence). Effects of fit testing of HPDs with extensive instructions versus fit testing of HPDs with simple instructions Fit testing of foam earplugs with extensive instructions probably improves their attenuation (MD 8.62 dB, 95% CI 6.31 to 10.93; 1 study, 321 participants; moderate-certainty evidence) and also the pass rate of sufficient attenuation (risk ratio (RR) 1.75, 95% CI 1.44 to 2.11; 1 study, 321 participants; moderate-certainty evidence) when compared to fit testing with simple instructions immediately after the test. This is significant because every 3 dB decrease in noise exposure level halves the sound energy entering the ear. No RCTs reported on the long-term effectiveness of the HPD fit testing with extensive instructions. AUTHORS' CONCLUSIONS: HPD fit testing accompanied by simple instructions probably does not improve noise attenuation from foam and premoulded earplugs. Testing the fit of foam and premoulded earplugs with extensive instructions probably improves attenuation and PAR pass rate immediately after the test. The effects of fit testing associated with training to improve attenuation may vary with types of HPDs and training methods. Better-designed trials with larger sample sizes are required to increase the certainty of the evidence.

Effects of Noise and Chemical Exposure on Peripheral and Central Auditory Pathways in Normal-hearing Workers.

Objectives: To assess the effects of noise and chemical exposure on peripheral and central auditory pathways in normal-hearing workers exposed to chemicals or high noise levels and compare the groups with each other and with workers not exposed to either of these agents. Methods: A total of 54 normal-hearing workers were divided into three groups (chemical, noise, control) and submitted to the following assessments: conventional and extended high-frequency pure-tone audiometry; transient and distortion-product otoacoustic emissions, the inhibitory effect of the efferent auditory pathway; and Staggered Spondaic Word (SSW) and Pitch Pattern Sequence (PPS) test. Results: There were no significant differences between the groups in extended high-frequency hearing thresholds. Significantly lower amplitudes were observed in the noise group for otoacoustic emissions. There were significantly more absences of the inhibitory effect of the efferent system in the noise group. There was no difference between the groups in the SSW test, while in PPS, the noise group performed worse than the control group. Conclusion: These findings suggest that noise exposure produced deleterious effects on the workers' peripheral and central auditory systems, despite their normal hearing thresholds. The chemical group did not have significantly different results from those of the control group. It is important that individuals exposed to noise or chemicals have their auditory pathways monitored with complementary assessments.

Hearing Loss and Cognitive Function: Baseline Findings From the Brazilian Longitudinal Study of Adult Health: ELSA-Brasil.

OBJECTIVE: Hearing loss (HL) has been associated with cognitive impairment in high-income countries. However, no study has investigated this association in low- and middle-income countries. Therefore, our aim was to investigate the association between cognitive function and HL in the Brazilian Longitudinal Study of Adult Health. DESIGN: Cross-sectional analysis of Longitudinal Study of Adult Health (ELSA-Brasil) with 802 individuals (35-74 years old). Hearing was measured using pure-tone audiometry. A pure-tone average (s) of thresholds at 500, 1000, 2000, and 4000 Hz was calculated. HL was defined as a PTA above 25 dB in the better ear or either ear, as a categorical variable. Cognitive performance was measured using the Consortium to Establish a Registry for Alzheimer's Disease word list memory test, the semantic and phonemic verbal fluency (VF) tests, and the Trail Making test version B. To investigate the association between cognitive performance and HL, we used linear regression models adjusted for sociodemographic and clinical variables. RESULTS: Of the total of participants, 7.6% had HL. After adjustment for sociodemographic and health confounding variables, only VF was associated with HL; a 10 dB increase in the PTA in the better ear was associated with worse performance in the phonemic VF test (ß = -0.115 [95% CI, -0.203 to -0.027], p = 0.01). We found a significant interaction between HL and age in the VF domain ( p = 0.01). HL was related to poor VF performance among older adults only. CONCLUSION: In a community-dwelling sample of most middle-aged adults, objectively measured HL was associated with lower VF. These results should be evaluated with caution, given the likelihood of residual confounding and the fact that only VF showed an association with HL.

Effects of hearing protector devices on speech intelligibility: the importance of individualized assessment.

Objectives. This study aimed to compare speech intelligibility in noise with and without hearing protection devices (HPDs). Methods. Fifty-one workers were distributed into three groups: noise-induced hearing loss group (NIHLG), normally hearing noise-exposed group (NG) and normally hearing non-exposed to noise group (CG). A free field system was used to emit monosyllables (65, 70 and 75 dB) and pink noise in different signal-to-noise ratios (SNRs) (0, -5, -10 and -15). Results. In situations with HPDs, all groups showed a decrease in the percentage of correct responses with an increase in noise level. The HPD had little effect on speech intelligibility in the NIHLG and NG. Considering the effect caused by the HPD on speech intelligibility, it was observed that the group with the greatest loss was the CG for SNRs of -5, -10 and -15. Conclusion. Although speech intelligibility is influenced by the hearing threshold, the noise level and SNR are crucial for good speech intelligibility, either with or without an HPD. It is highlighted that the NG had worse results when compared with the CG, which may indicate changes in the auditory pathway resulting from continuous noise exposure, even in the absence of changes in the audiometric thresholds.

Oxidative Stress as a Risk Factor for Hearing Changes in HIV-positive Normal Listeners.

OBJECTIVES: Human immunodeficiency virus-positive (HIV+) individuals can experience a decrease in antioxidants. Such deficiency can make inner ear cells and synapses more vulnerable to oxidative stress, resulting in auditory alterations, even in the presence of normal thresholds. This study aims to compare the audiological findings of HIV+ patients (with and without exposure to anti-retroviral treatment) to those of healthy individuals. METHODS: This was a cross-sectional observational study, comprising 42 normal-hearing adults divided into the Control Group (CG), without HIV; Group I (GI), HIV+, without exposure to the highly active anti-retroviral therapy (HAART); Group II (GII), HIV+, with exposure to HAART. All participants underwent conventional audiometry (0.25-8 kHz), high-frequency audiometry (9-20 kHz), transient evoked otoacoustic emissions (TEOAEs), efferent auditory pathway's inhibitory effect assessment, brainstem auditory evoked potentials (BAEPs), and cognitive potential (P300). RESULTS: In the comparison of the hearing thresholds between the groups, there was a statistically significant difference for most of the frequencies assessed (GII presented hearing thresholds significantly poor when compared with other groups). The presence of TEOAE and the inhibitory effect was also verified in a significantly higher number of individuals in the CG than in the other groups. As for the BAEP, there was a statistically significant difference for the interpeak intervals I-V (GII showed higher values when compared with CG). For P300, there were no statistically significant differences. CONCLUSION: Normal-hearing HIV+ individuals (with and without exposure to HAART) presented with poor performance in the audiological procedures, suggesting the presence of auditory alterations even in the presence of normal-hearing thresholds.

Tablet-based tele-audiometry: Automated hearing screening for schoolchildren.

Introduction: To assess the performance of a tablet-based tele-audiometry method for automated hearing screening of schoolchildren through a comparison of the results of various hearing screening approaches. Methods: A total of 244 children were evaluated. Tablet-based screening results were compared with gold-standard pure-tone audiometry. Acoustic immittance measurements were also conducted. To pass the tablet-based screening, the children were required to respond to at least two out of three sounds for all the frequencies in each ear. Several hearing screening methods were analysed: exclusively tablet-based (with and without 500 Hz checked) and combined tests (series and parallel). The sensitivity, specificity, positive and negative predictive values and accuracy were calculated. Results: A total of 9.43% of children presented with mild to moderate conductive hearing loss (unilateral or bilateral). Diagnostic values varied among the different hearing screening approaches that were evaluated: sensitivities ranged from 60 to 95%, specificities ranged from 44 to 91%, positive predictive values ranged from 15 to 44%, negative predictive values ranged from 95 to 99%, accuracy values ranged from 49 to 88%, and area under curve values ranged from 0.690 to 0.883. Regarding diagnostic values, the highest results were found for the tablet-based screening method and for the series approach. Discussion: Compared with the results obtained by conventional audiometry and considering the diagnostic values of the different hearing screening approaches, the highest diagnostic values were generally obtained using the automated hearing screening method (including 500 Hz). Thus, this application, which was developed for the tablet computer, was shown to be a valuable hearing screening tool for use with schoolchildren. Therefore, we suggest that this hearing screening protocol has the potential to improve asynchronous tele-audiology service delivery.

Oxidative stress as a risk factor for haring changes in HIV-positive normal listeners

OBJECTIVES: Human immunodeficiency virus-positive (HIV+) individuals can experience a decrease in antioxidants. Such deficiency can make inner ear cells and synapses more vulnerable to oxidative stress, resulting in auditory alterations, even in the presence of normal thresholds. This study aims to compare the audiological findings of HIV+ patients (with and without exposure to anti-retroviral treatment) to those of healthy individuals. METHODS: This was a cross-sectional observational study, comprising 42 normal-hearing adults divided into the Control Group (CG), without HIV; Group I (GI), HIV+, without exposure to the highly active anti-retroviral therapy (HAART); Group II (GII), HIV+, with exposure to HAART. All participants underwent conventional audiometry (0.25-8 kHz), high-frequency audiometry (9-20 kHz), transient evoked otoacoustic emissions (TEOAEs), efferent auditory pathway's inhibitory effect assessment, brainstem auditory evoked potentials (BAEPs), and cognitive potential (P300). RESULTS: In the comparison of the hearing thresholds between the groups, there was a statistically significant difference for most of the frequencies assessed (GII presented hearing thresholds significantly poor when compared with other groups). The presence of TEOAE and the inhibitory effect was also verified in a significantly higher number of individuals in the CG than in the other groups. As for the BAEP, there was a statistically significant difference for the interpeak intervals I-V (GII showed higher values when compared with CG). For P300, there were no statistically significant differences. CONCLUSION: Normal-hearing HIV+ individuals (with and without exposure to HAART) presented with poor performance in the audiological procedures, suggesting the presence of auditory alterations even in the presence of normal-hearing thresholds.

The study of attenuation levels and the comfort of earplugs.

INTRODUCTION: This study aimed to analyze and compare four different types of earplugs, divided into premolded plugs and foam plug models, in relation to the level of attenuation, comfort, and the size of the external acoustic meatus (EAM) in an attempt to identify how these variables influence the choice of specific hearing protection devices (HPDs). MATERIALS AND METHODS: A cross-sectional observational study was performed in a sample of 49 participants, oriented toward the ideal placement of four HPDs, two premolded and two foam plugs (3M™). The procedures included otoscopy, EAM diameter measurement using an otometer, EAM volume measurement via an acoustic impedance test, and the obtainment of the bilateral personal attenuation rating (PAR) for each HPD using the E-A-Rfit™ Validation System (3M™). The Bipolar Comfort Rating Scale (BCRS) instrument was applied twice for each individual: once after the evaluations with the premolded HPDs and again after the evaluations with the foam plug HPDs. Then, each participant was asked which was his/her favorite protector. RESULTS: The volume of the EAM was not directly related to the diameter of the EAM. The attenuation did not interfere with the HPD preference, and the PAR of the foam plug was significantly higher regardless of the preferred HPD. Regarding the BCRS, the variables "Placement," "Complexity," and "Occlusion Effect" had higher scores for premolded HPDs and had a direct relationship with the type of preferred HPD. CONCLUSION: Attention to the use of HPDs should be personalized, taking into account the needs of each individual, considering not only the attenuation, but also the user's reported well-being.

Tablet-Based Hearing Screening Test.

INTRODUCTION: Hearing loss (HL) affects people worldwide, many of whom are children. Especially in developing countries, epidemiological data on the prevalence of HL are insufficient to implement effective health promotion programs. In this preliminary study with young adults, we describe and validate a tablet-based hearing screening test developed for interactive remote hearing screening and compare the performance of an audiometry screening tablet application with conventional audiometry. In addition, the sensitivity, specificity, and predictive values of the tablet-based method and the concordance between the two methods were analyzed. METHODS: Thirty volunteers participated in a double-blind study assessing two auditory threshold screening methods: tablet-based hearing screening and sweep audiometry. For both methods, a correct response to a minimum of two tones out of three emitted at 20 dBHL for the frequencies of 1, 2, and 4 kHz and 30 dBHL for 0.5 kHz in both ears, was considered a negative screening result (normal hearing), whereas hearing impairment was considered a positive screening result. RESULTS: According to both methods, 26 participants had normal hearing and four had HL. The Kappa coefficient indicated perfect concordance between methods. The tablet-based hearing screening method had a sensitivity of 100% (confidence interval [CI]: 30.5-100.0), a specificity of 100% (CI: 87.1-100.0), a positive predictive value of 100% (CI: 30.5-100.0), and a negative predictive value of 100% (CI: 87.1-100.0). CONCLUSIONS: The tablet-based hearing screening test was shown to be a reliable and an accurate method for hearing screening that can be used effectively in places with Internet access and where local audiologists are not available.

Diabetes mellitus and sensorineural hearing loss: is there an association? Baseline of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil).

OBJECTIVES:: Although several studies have investigated the effects of diabetes on hearing loss, the relationship between these two conditions remains unclear. Some studies have suggested that diabetes may cause sensorineural hearing loss, whereas others have failed to find an association. The biggest challenge in investigating the association between diabetes and hearing loss is the presence of confounding variables and the complexity of the auditory system. Our study investigated the association between diabetes and sensorineural hearing loss. We evaluated the influence of time from diabetes diagnosis on this association after controlling for age, gender, and hypertension diagnosis and excluding those subjects with exposure to noise. METHODS:: This cross-sectional study evaluated 901 adult and elderly Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) participants from São Paulo, Brazil who underwent audiometry testing as part of ELSA-Brasil's baseline assessment. RESULTS:: Hearing thresholds and speech test results were significantly worse in the group with diabetes than in the group without diabetes. However, no significant differences were found between participants with and without diabetes after adjusting for age, gender, and the presence of hypertension. Hearing thresholds were not affected by occupational noise exposure in the groups with and without diabetes. In addition, no association between the duration of diabetes and hearing thresholds was observed after adjusting for age, gender, and hypertension. CONCLUSION:: We found no association between the duration of diabetes and worse hearing thresholds after models were adjusted for age, gender, and the presence of hypertension.

Diabetes mellitus and sensorineural hearing loss: is there an association? Baseline of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

OBJECTIVES: Although several studies have investigated the effects of diabetes on hearing loss, the relationship between these two conditions remains unclear. Some studies have suggested that diabetes may cause sensorineural hearing loss, whereas others have failed to find an association. The biggest challenge in investigating the association between diabetes and hearing loss is the presence of confounding variables and the complexity of the auditory system. Our study investigated the association between diabetes and sensorineural hearing loss. We evaluated the influence of time from diabetes diagnosis on this association after controlling for age, gender, and hypertension diagnosis and excluding those subjects with exposure to noise. METHODS: This cross-sectional study evaluated 901 adult and elderly Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) participants from São Paulo, Brazil who underwent audiometry testing as part of ELSA-Brasil’s baseline assessment. RESULTS: Hearing thresholds and speech test results were significantly worse in the group with diabetes than in the group without diabetes. However, no significant differences were found between participants with and without diabetes after adjusting for age, gender, and the presence of hypertension. Hearing thresholds were not affected by occupational noise exposure in the groups with and without diabetes. In addition, no association between the duration of diabetes and hearing thresholds was observed after adjusting for age, gender, and hypertension. CONCLUSION: We found no association between the duration of diabetes and worse hearing thresholds after models were adjusted for age, gender, and the presence of hypertension.

Audiological and electrophysiological assessment of professional pop/rock musicians.

In the present study, we evaluated peripheral and central auditory pathways in professional musicians (with and without hearing loss) compared to non-musicians. The goal was to verify if music exposure could affect auditory pathways as a whole. This is a prospective study that compared the results obtained between three groups (musicians with and without hearing loss and non-musicians). Thirty-two male individuals participated and they were assessed by: Immittance measurements, pure-tone air conduction thresholds at all frequencies from 0.25 to 20 kHz, Transient Evoked Otoacoustic Emissions, Auditory Brainstem Response (ABR), and Cognitive Potential. The musicians showed worse hearing thresholds in both conventional and high frequency audiometry when compared to the non-musicians; the mean amplitude of Transient Evoked Otoacoustic Emissions was smaller in the musicians group, but the mean latencies of Auditory Brainstem Response and Cognitive Potential were diminished in the musicians when compared to the non-musicians. Our findings suggest that the population of musicians is at risk for developing music-induced hearing loss. However, the electrophysiological evaluation showed that latency waves of ABR and P300 were diminished in musicians, which may suggest that the auditory training to which these musicians are exposed acts as a facilitator of the acoustic signal transmission to the cortex.

Perfil das classes especiais freqüentadas por surdos atendidos no setor de audiologia educacional da FMUSP / Profile of special classes followed by deaf children attending the educational audiology division of the medicine school of the University of S los o Paulo

Este artigo teve por objetivo traçar um perfil e analisar algumas características das classes especiais de escolas regulares freqüentadas pelos surdos atendidos no Setor de Audiologia Educacional da FMUSP. Foram realizadas visitas às escolas e aplicados questionários a professores e/ou ao corpo técnico-administrativo. O questionário abrangia aspectos relacionados a recursos humanos, população atendida, critérios para formação de de sala de aula (classes especiais), filosofia de alfabetização, modalidade de comunicação e conteúdo curricular. Em seguida, as respostas dos questionários referentes a cinco escolas regulares da rede pública de ensino, contendo classes especiais, foram analisados. Os resultados obtidos denotam que alguns dos aspectos, na prática, não estão de acordo com o que é proposto como ideal pela literatura especializada e por algumas leis vigentes, que regem a educação especial (AU)

Perfil das classes especiais frequentadas por surdos atendidos no setor de audiologia educacional da FMUSP / Profile of special classes followed by deaf children attending the educational audiology division of the medicine school of the University of Säo Paulo

Este artigo teve por objetivo traçar um perfil e analisar algumas características das classes especiais de escolas regulares frequentadas pelos surdos atendidos no Setor de Audiologia Educacional da FMUSP. Foram realizadas visitas às escolas e aplicados questionários a professores e/ou ao corpo técnico-administrativo. O questionário abrangia aspectos relacionados a recursos humanos, populaçäo atendida, critérios para formaçäo de sala de aula (classes especiais), filosofia de alfabetizaçäo, modalidade de comunicaçäo e conteúdo curricular. Em seguida, as respostas dos questionários referentes a cinco escolas regulares da rede pública de ensino, contendo classes especiais, foram analisados. Os resultados obtidos denotam que alguns dos aspectos, na prática, näo estäo de acordo com o que é proposto como ideal pela literatura especializada e por algumas leis vigentes, que regem a educaçäo especial