Attitudes to noise in young adults and associated factors: adaptation of the youth attitude to noise scale into Spanish using item response theory analysis.

OBJECTIVE: This study aimed to identify the attitudes to noise in young adults and the possible effects of gender, age, and a positive history of auditory symptoms related to recreational noise exposure on the attitudes to noise in this population. DESIGN: The Youth Attitude to Noise (YANS) and the hearing symptom description (HSD) scales were adapted into Spanish to be used with young adults. The validity was determined using factor analyses and Item Response Theory (IRT) models. Linear regression models were used to determine whether the YANS scores were associated with gender, age, and auditory symptoms. STUDY SAMPLE: Both instruments were given to a sample of 728 Chilean young adults. Data obtained from this sample was used to determine the YANS and HSD scales' validity and to assess the effects of gender, age, and auditory symptoms on attitudes. RESULTS: Our results showed that the YANS and HSD scales had adequate validity and reliability. Differences in the items' capacity to discriminate attitudes to noise were noted using the IRT model. Auditory symptoms were significantly associated with the YANS scores. CONCLUSIONS: The attitudes to noise in Chilean young adults are influenced by self-perception of auditory symptoms, age, and gender.

Social determinants of health associated with attitudes towards hearing loss and hearing aids in older adults fitted in a Latin American country: validation of the ALHQ questionnaire into Spanish.

OBJECTIVE: This study aimed to evaluate the association between certain social determinants of health (i.e. educational level, income, and social support) and attitudes towards hearing loss and hearing aids among older adults with hearing loss fitted in a Latin American country. DESIGN: Older adults were asked about their attitudes towards hearing loss and hearing aids, years of formal education, income, social support, perception of having a hearing disability, and social pressure when using the hearing aid. To do so, we adapted the Attitudes towards Loss of Hearing Questionnaire (S-ALHQ) into Spanish. All the questionnaires were conducted as structured interview. STUDY SAMPLE: Two hundred fifty-two older hearing aids users were recruited from a public hospital in Chile. RESULTS: The S-ALHQ showed adequate validity, along with good reliability. The multivariate models showed that educational level and social support were the social determinants of health negatively associated with the attitudes. Aided hearing disability and social pressure to use hearing aids were the co-variables associated with S-ALHQ scores. CONCLUSIONS: The study showed a significant relationship between specific social determinants of health and attitudes towards hearing loss and hearing aids. These attitudes should be considered when implementing rehabilitation programs for older adults with hearing loss.

Supra-threshold deficits in normal hearing military recruits exposed to impulse noise.

The aim of this study was to determine the effect of impulse noise exposure on various proxy measures of cochlear synaptopathy in young military recruits. A total of 27 military recruits with exposure to firearm and artillery noise and 13 non exposed participants were recruited. All presented with normal hearing thresholds and the presence of distortion product otoacoustic emissions (DPOAEs). The Noise Exposure Structured Interview (NESI) was used to quantify noise exposure. Speech perception in noise (SPiN), equivalent rectangular bandwidth (ERB) of auditory filters, auditory brainstem response wave I amplitude, wave I amplitude growth function, wave I/V amplitude ratio, wave V latency, wave V latency shift with ipsilateral noise, and the summating potential/action potential ratio of the electrocochleography were measured. In military participants, SPiN was worse, ERB at 4 kHz was larger, wave I amplitude at 75 dBnHL was reduced, and wave V latency was delayed. However, no significant correlations were observed between NESI and auditory measures, once multiplicity of tests was controlled for. These results suggest that military recruits may exhibit supra-threshold deficits, despite presenting with normal hearing thresholds and presence of DPOAEs. Future studies should include a measure of auditory filters in their test battery.

Association Between the Right Ear Advantage in Dichotic Listening and Interaural Differences in Sensory Processing at Lower Levels of the Auditory System in Older Adults.

OBJECTIVE: Current evidence suggests that an enhanced right ear advantage (REA) in dichotic listening (DL) among older adults may originate from age-related structural changes in the corpus callosum and age-related decline in cognitive processes. Less is known about the effect of information processing at lower portions of the auditory system on DL performance. The present study investigates whether interaural differences (ID) in sensory processing at lower levels of the auditory system are associated with the magnitude of the REA in DL among older adults. DESIGN: Sixty-eight older adults participated in the study. Participants were assessed with a DL test using nonforced (NF) and forced attention paradigms. Hearing sensitivity, transient-evoked otoacoustic emission (TEOAE), contralateral suppression of TEOAE, a proxy measure of medial olivocochlear activation, and auditory brainstem response to speech stimuli (speech-ABR) were tested in both ears separately. The ID in sensory processing at lower levels of the auditory system was derived by calculating the difference between the RE and LE for each auditory measure. Bivariate and multivariate regression models were performed. One multivariate model for each DL paradigm (NF and forced attention) was independently constructed. Measures of cognitive speed of processing and cognitive flexibility were accounted for in the regression models. RESULTS: For both multivariate regression models, ID in pure-tone thresholds and ID in MOC suppression of TEOAE were significantly associated with the magnitude of the REA for DL among older adults. Cognitive measures of speed of processing and cognitive flexibility also contributed to the magnitude of the REA. CONCLUSION: These results suggest that ID in sensory processing at lower levels of the auditory system account, at least in part, for the increased magnitude of the REA in DL among older adults.

Acoustical role of ear canal in exposure to the typical occupational noise levels.

Background: Exposure to noise associated with injuries has become a public health issue in recent years. This study aimed to show the role of the acoustical structure of the ear canal on the typical occupational sound pressure levels at different frequencies. Methods: This cross-sectional study was done on 20-30-year-old participants. White noise was used at 3 levels, including 75, 85, and 95 dB as the stimulus sound pressure levels (SSPLs). The speakers had a 1.5-meter distance from the participants and at the height of 87 centimeters from the lab ground and were located in front of the participants. The SSPLs were measured outside (cavum part of the external ear) and inside the right ear of each participant. Measurements were done at the total sound pressure level and in the 1/1 octave frequencies. The duration for each measurement was 10 seconds. The independent sample t test was used for the statistical analysis, and the equality of means were rejected at p<0.05. Results: There were 30 (50%) males out of the 60 participants. The mean ± SD for the age of all the participants was 23.29±2.93 years. The total sound pressure level difference between the inside and outside of the ears of male and female participants was statistically significant (p<0.001) at the stimulus sound pressure levels. The peak resonance was observed in the frequencies 2000 Hz and 8000 Hz for males and 8000 Hz for females. Conclusion: The ear canal can amplify the sounds and increase the sound pressure levels. This amplification was found to be greater for males than for females.

Association between speech perception in noise and electrophysiological measures: an exploratory study of possible techniques to evaluate cochlear synaptopathy in humans.

Objective: The primary aim of this study was to investigate whether scores for a speech-in-noise test were associated with the results of two electrophysiological techniques mainly targeting low spontaneous rate, high-threshold auditory fibres.Design: Cross-sectional study. Participants were evaluated with the hearing-in-noise test (HINT), along with the Auditory Brainstem Response (ABR) with and without ipsilateral noise. The wave V/I amplitude ratio for the ABR without ipsilateral noise and ABR wave V latency shift in the presence of ipsilateral noise were obtained.Study sample: Twenty adults aged between 20 and 34 years (10 females) who did not report occupational exposure to noise were selected. All participants presented with normal hearing thresholds (0.250-8 kHz) and the presence of distortion product otoacoustic emissions, bilaterally.Results: A significant association between the wave V/I amplitude ratio for the left ear and the HINT scores for the left ear was found.Conclusions: Based on the results of this study, in normal-hearing listeners, the wave V/I ratio is associated with speech-in-noise performance, specifically in the left ear. This non-invasive procedure has the potential to be used in clinical populations who present with speech-in-noise difficulties despite having normal audiograms.

Adaptation of the "active communication education" programme into Spanish for older adults with hearing loss.

Objective: To adapt the Active Communication Education (ACE) programme into Spanish. In addition, this study aimed at determining the effects of the adapted ACE programme on the social/emotional impacts of hearing loss and hearing functioning in a group of older adults with hearing loss who do not wear hearing aids.Design: This was an exploratory cohort study. Study group participants received the newly adapted ACE programme and control group participants received a cognitive stimulation programme. The Shortened Hearing Handicap Inventory for the Elderly in Spanish (HHIE-S) and the Spanish version of the Amsterdam Inventory for Auditory Disability and Handicap (S-AIADH) were carried out before and after each programme.Study sample: Sixty-six older adults with hearing loss and who did not wear hearing aids were randomly assigned to either an ACE group (n = 30) or a cognitive stimulation group (n = 36).Results: Participants who received the ACE programme showed a significantly larger improvement for the S-AIADH than did the cognitive stimulation group participants.Conclusions: The ACE programme has been adapted into Spanish for use with Chilean older adults with hearing loss. The results show that older adults report better functioning in listening situations after attending the sessions of the adapted ACE programme.

Exposure to noise and ototoxic chemicals in the Australian workforce.

OBJECTIVE: To determine the current prevalence of exposure to workplace noise and ototoxic chemicals, including co-exposures. METHOD: A cross-sectional telephone survey of nearly 5000 Australian workers was conducted using the web-based application, OccIDEAS. Participants were asked about workplace tasks they performed and predefined algorithms automatically assessed worker's likelihood of exposure to 10 known ototoxic chemicals as well as estimated their full shift noise exposure level (LAeq,8h) of their most recent working day. Results were extrapolated to represent the Australian working population using a raked weighting technique. RESULTS: In the Australian workforce, 19.5% of men and 2.8% of women exceeded the recommended full shift noise limit of 85 dBA during their last working day. Men were more likely to be exposed to noise if they were younger, had trade qualifications and did not live in a major city. Men were more likely exposed to workplace ototoxic chemicals (57.3%) than women (25.3%). Over 80% of workers who exceeded the full shift noise limit were also exposed to at least one ototoxic chemical in their workplace. CONCLUSION: The results demonstrate that exposures to hazardous noise and ototoxic chemicals are widespread in Australian workplaces and co-exposure is common. Occupational exposure occurs predominantly for men and could explain some of the discrepancies in hearing loss prevalence between genders.

Effects of auditory and socio-demographic variables on discontinuation of hearing aid use among older adults with hearing loss fitted in the Chilean public health sector.

BACKGROUND: The percentage of older adults with hearing loss who stop using their hearing aids and the variables associated with this phenomenon have not been systematically investigated in South America. This problem is relevant to the region since countries such as Colombia, Brazil and Chile have public programmes that provide hearing aids to older adults. The aims of this study were to determine the percentage of older adults fitted with a hearing aid at a public hospital in Chile who subsequently stop using it and the auditory and socio-demographic variables associated with the hazard of discontinuing hearing aid use. METHODS: A group that included 355 older adults who had been fitted with a hearing aid was studied retrospectively. In a structured interview, participants were asked about socio-demographic variables and answered part of the Chilean National Survey on Health, evaluating self-perceived hearing loss and responding to questions about discontinuation of hearing aid use and their satisfaction with the device. Survival models were applied to determine the hazard of stopping hearing aid use in relation to the variables of interest. RESULTS: The rate of discontinuation of hearing aid use reached 21.7%. Older adults stopped using their hearing aids mainly during the first 5-6 months post-fitting, and then this number steadily increased. The income fifth quintile was 2.56 times less likely to stop using the hearing aid compared to the first. Those who self-reported that they could not hear correctly without the hearing aid were 2.62 times less likely to stop using it compared to those who reported normal hearing. The group that was very dissatisfied with the hearing aid was 20.86 times more likely to discontinue use than those who reported satisfaction with the device. CONCLUSIONS: Socio-demographic variables such as economic income and auditory factors such as self-perceived hearing loss and satisfaction with the device were significantly associated with the hazard of stopping hearing aid use. Self-perceived hearing loss should be considered part of the candidacy criteria for hearing aids in older adults in Chile and other (developing) countries.

Jet fuel exposure and auditory outcomes in Australian air force personnel.

BACKGROUND: Animal data suggest that jet fuels such as JP-8 are associated with hearing deficits when combined with noise and that the effect is more pronounced than with noise exposure alone. Some studies suggest peripheral dysfunction while others suggest central auditory dysfunction. Human data are limited in this regard. The aim of this study was to investigate the possible chronic adverse effects of JP-8 combined with noise exposure on the peripheral and central auditory systems in humans. METHODS: Fifty-seven participants who were current personnel from the Royal Australian Air Force were selected. Based on their levels of exposure to jet fuels, participants were divided into three exposure groups (low, moderate, high). Groups were also categorised based on their noise exposure levels (low, moderate, high). All participants were evaluated by tympanometry, pure-tone audiometry (1-12 kHz), distortion product otoacoustic emissions (DPOAEs), auditory brainstem response (ABR), words-in-noise, compressed speech, dichotic digit test, pitch pattern sequence test, duration pattern sequence test and adaptive test of temporal resolution. All auditory tests were carried out after the participants were away from the Air Force base for a minimum of two weeks, thus two weeks without jet fuel and noise exposure. RESULTS: Jet fuel exposure was significantly associated with hearing thresholds at 4 and 8 kHz; average hearing thresholds across frequencies in the better ear; DPOAEs at 2.8, 4 and 6 kHz; ABR wave V latency in the right ear; compressed speech and words-in-noise. Further analyses revealed that participants with low exposure level to jet fuels showed significantly better results for the aforementioned procedures than participants with moderate and high exposure levels. All results were controlled for the covariates of age and noise exposure levels. CONCLUSIONS: The results suggest that jet fuel exposure, when combined with noise exposure, has an adverse effect on audibility in humans. Taking all the test results into consideration, jet fuel exposure combined with noise exposure specifically seems to affect the peripheral hearing system in humans.

Use of the kurtosis statistic in an evaluation of the effects of noise and solvent exposures on the hearing thresholds of workers: An exploratory study.

The aim of this exploratory study was to examine whether the kurtosis metric can contribute to investigations of the effects of combined exposure to noise and solvents on human hearing thresholds. Twenty factory workers exposed to noise and solvents along with 20 workers of similar age exposed only to noise in eastern China were investigated using pure-tone audiometry (1000-8000 Hz). Exposure histories and shift-long noise recording files were obtained for each participant. The data were used in the calculation of the cumulative noise exposure (CNE) and CNE adjusted by the kurtosis metric for each participant. Passive samplers were used to measure solvent concentrations for each worker exposed to solvents over the full work shift. Results showed an interaction between noise exposure and solvents for the hearing threshold at 6000 Hz. This effect was observed only when the CNE level was adjusted by the kurtosis metric.

Prevalence and associated factors of hearing aid use among older adults in Chile.

OBJECTIVE: The aim of this study was to determine the prevalence of use of hearing aids by older adults in Chile and the influence of some variables such as education level, income level and geographic area of residence on the prevalence of hearing aids. DESIGN: A national cross-sectional survey which was carried out in 2009. STUDY SAMPLE: A representative sample of 4766 Chilean older adults aged 60 years and above. RESULTS: The percentage of older adults in Chile who self-reported hearing problems and used hearing aids was 8.9%. Such prevalence increased for adults living in urban areas and for those who knew about the new Chilean programme of universal access to health services (AUGE). For older adults who did not know about this programme, significant associations between the use of hearing aids and the variables of age, geographic area of residence, and income level were found. CONCLUSIONS: People's knowledge about AUGE programme may positively influence the use of hearing aids, although a direct effect cannot be attributed.

Adverse effects of pesticides on central auditory functions in tobacco growers.

OBJECTIVE: To investigate the effects of exposure to pesticides on the central auditory functions (CAF) of Brazilian tobacco growers. DESIGN: This was a cross-sectional study carried out between 2010 and 2012. Participants were evaluated with two behavioural procedures to investigate CAF, the random gap detection test (RGDT) and the dichotic digit test in Portuguese (DDT). STUDY SAMPLE: A total of 22 growers exposed to pesticides (study group) and 21 subjects who were not exposed to pesticides (control group) were selected. RESULTS: No significant differences between groups were observed for pure-tone thresholds. A significant association between pesticide exposure and the results for RGDT and DDT was found. Significant differences between pesticide-exposed and nonexposed subjects were found for RGDT frequency average and DDT binaural average, when including age and hearing level as covariates. Age was significantly associated with RGDT frequency average, DDT left ear score, DDT binaural average and DDT right ear advantage. Hearing levels were not significantly associated with any of the test scores. The relative risk of failing the DDT and RGDT for the study group was 1.88 (95% CI: 1.10-3.20) and 1.74 (95% CI: 1.06-2.86), respectively, as compared with the control group. CONCLUSIONS: The results showed that tobacco growers exposed to pesticides exhibited signs of central auditory dysfunction characterised by decrements in temporal processing and binaural integration processes/abilities.

Assessment of Central Auditory Processing in Children Using a Novel Tablet-Based Platform: Application for Low- and Middle-Income Countries.

OBJECTIVE: Evaluate whether a portable, tablet-based central auditory processing (CAP) test system using native language training videos and administered by minimally trained community health workers can produce CAP results comparable to previously published norms. Our secondary aim was to determine subject parameters that influence test results. STUDY DESIGN: Cross-sectional study. SETTING: Community-based settings in Chontales, Nicaragua, New Hampshire, and Florida. PATIENTS: English- and/or Spanish-speaking children and adolescents (n = 245; average age, 12.20 yr; range, 6-18 yr). MAIN OUTCOME MEASURES: Completion of the following tests with responses comparable to published norms: Pure-tone average (PTA), gap detection threshold (GDT), fixed-level frequency threshold, masking level difference (MLD), Hearing in Noise Test (HINT), Dichotic Digits Test (DDT), and Frequency Pattern Recognition (FPR) test. RESULTS: GDT, HINT, and DDT had comparable results to previously published normative values. MLD and FPR results differed compared with previously published normative values. Most CAP tests (MLD, GDT, HINT) results were independent of age and PTA (p = 0.1-0.9). However, DDT was associated with age and PTA (p < 0.0001). CONCLUSIONS: Pediatric CAP testing can be successfully completed in remote low- and middle- income country environments using a tablet-based platform without the presence of an audiologist. Performance on DDT improved with age but deteriorated with hearing loss. Further investigation is warranted to assess the variability of FPR.

Xylene-induced auditory dysfunction in humans.

OBJECTIVES: Animal data indicate that xylene induces cochlear dysfunction, characterized by the loss of outer hair cells. There is little evidence regarding xylene-induced ototoxicity in humans. The aim of the study was to investigate the possible adverse effects of xylene on the peripheral and central auditory system in humans. DESIGN: A total of 30 medical laboratory workers who had been exposed to a mixture of xylene isomers, together with 30 nonexposed control participants matched for gender, age, and educational level were selected. Participants of both groups were not exposed to noise levels above 85 dBA time-weighted average. All participants were evaluated with a comprehensive audiological test battery, which included measures of peripheral and central auditory function. Peripheral auditory measures included pure-tone audiometry and distortion product otoacoustic emissions. Behavioral measures of central auditory function included a pitch pattern sequence test, an adaptive test of temporal resolution, a dichotic digit test, and a masking level difference test. The auditory brainstem response was used to objectively evaluate the function of the auditory pathways at the brainstem level. Speech perception in quiet and in noise was evaluated using the Hearing In Noise Test (HINT). The xylene-exposed participants were extensively evaluated with regard to their exposure to both noise and xylene. Noise dosimetry was conducted over an 8-hr work shift to obtain noise-exposure levels for each xylene-exposed worker. Airborne xylene concentrations were obtained at 11 different workstations throughout the medical laboratories, and methyl hippuric acid levels per gram of creatinine in urine were obtained for each xylene-exposed subject. Finally, a detailed interview exploring current and past solvent and noise exposure was conducted. RESULTS: The xylene-exposed participants showed significantly worse pure-tone thresholds in comparison with the nonexposed participants. The xylene-exposed participants demonstrated significantly worse results than the control group participants for the pitch pattern sequence test, dichotic digit test, HINT, and the auditory brainstem response (absolute and interpeak latencies). No significant differences between the xylene-exposed and nonexposed participants were observed for distortion product otoacoustic emissions, adaptive test of temporal resolution, or the masking level difference test. A significant correlation between the concentrations of methyl hippuric acid in urine and pure-tone thresholds (2 to 8 kHz) was found in xylene-exposed workers. Also, participants with high cumulative dose of xylene exposure presented with poorer test results than participants with low cumulative dose of xylene exposure. CONCLUSIONS: The results of the present research suggest that xylene is associated with adverse central auditory effects and poorer sound detection abilities in humans. A major limitation of the study is that the results found among xylene-exposed participants cannot be proved to be permanent, and thus further research should be conducted to clarify this limitation. Workers exposed to this chemical should be routinely evaluated with a comprehensive audiological test battery, to detect early signs of auditory dysfunction.

Auditory dysfunction associated with solvent exposure.

BACKGROUND: A number of studies have demonstrated that solvents may induce auditory dysfunction. However, there is still little knowledge regarding the main signs and symptoms of solvent-induced hearing loss (SIHL). The aim of this research was to investigate the association between solvent exposure and adverse effects on peripheral and central auditory functioning with a comprehensive audiological test battery. METHODS: Seventy-two solvent-exposed workers and 72 non-exposed workers were selected to participate in the study. The test battery comprised pure-tone audiometry (PTA), transient evoked otoacoustic emissions (TEOAE), Random Gap Detection (RGD) and Hearing-in-Noise test (HINT). RESULTS: Solvent-exposed subjects presented with poorer mean test results than non-exposed subjects. A bivariate and multivariate linear regression model analysis was performed. One model for each auditory outcome (PTA, TEOAE, RGD and HINT) was independently constructed. For all of the models solvent exposure was significantly associated with the auditory outcome. Age also appeared significantly associated with some auditory outcomes. CONCLUSIONS: This study provides further evidence of the possible adverse effect of solvents on the peripheral and central auditory functioning. A discussion of these effects and the utility of selected hearing tests to assess SIHL is addressed.

Screening for Auditory Processing Disorder in French-Speaking School-Age Children: A Pilot Study.

OBJECTIVES: A few clinical screening tools for auditory processing disorder (APD) are currently available. However, most of these tools are in English and cannot be used to screen individuals with a first language other than English. This study aimed to develop an APD screening test battery in French and to assess its psychometric properties in detecting school-age children at risk of APD. METHOD: Prior to their complete audiological APD assessment, 53 children (7-12 years old) were recruited from an audiology clinic. The APD assessment lasted between 2 and 3 hr, including 15-20 min for the screening test battery. The screening test battery was composed of four behavioral subtests and two questionnaires (parent and teacher). RESULTS: When combined, two among the four behavioral subtests showed a sensitivity of 100% and a specificity of 80%. CONCLUSION: The newly developed screening tool could help reduce the number of unnecessary APD assessments, therefore allowing early diagnosis in children with APD and increasing their chances of receiving adequate intervention.

Audiological Tests Used in the Evaluation of the Effects of Solvents on the Human Auditory System: A Mixed Methods Review.

This study aimed to scope the literature, identify knowledge gaps, appraise results, and synthesize the evidence on the audiological evaluation of workers exposed to solvents. We searched Medline, PubMed, Embase, CINAHL, and NIOSHTIC-2 up to March 22, 2021. Using Covidence, two authors independently assessed study eligibility, risk of bias, and extracted data. National Institute of Health Quality Assessment Tools was used in the quality evaluation of included studies; the Downs and Black checklist was used to assess the risk of bias. Of 454 located references, 37 were included. Twenty-five tests were studied: two tests to measure hearing thresholds, one test to measure word recognition in quiet, six electroacoustic procedures, four electrophysiological tests, and twelve behavioral tests to assess auditory processing skills. Two studies used the Amsterdam Inventory for Auditory Disability and Handicap. The quality of individual studies was mostly considered moderate, but the overall quality of evidence was considered low. The discrepancies between studies and differences in the methodologies/outcomes prevent recommending a specific test battery to assess the auditory effects of occupational solvents. Decisions on audiological tests for patients with a history of solvent exposures require the integration of the most current research evidence with clinical expertise and stakeholder perspectives.

Audiological findings of family farmers exposed to pesticides. / Achados audiológicos de agricultores familiares paranaenses expostos a agrotóxicos.

PURPOSE: To analyze the possible differences among the hearing of farmers and their families when compared to the population not exposed to pesticides. METHODS: Cross-sectional study with 70 smallholder family farmers (research group), with the mean age of 39.7 years, of both sexes and a mean of 23.7 years of exposure to pesticides. We included a control group with 71 participants of both sexes with the mean age of 39.5 years, not exposed to either noise or chemical substances, to compare the results. In stage 1, both groups were submitted to conventional and high-frequency audiometry, and acoustic immittance. In stage 2, only people with normal hearing were submitted to the evoked otoacoustic emissions and suppression effect on transient otoacoustic emissions. RESULTS: Significant differences were observed between the groups in the conventional pure-tone and in the high-frequency audiometry, as well as in the acoustic reflex. The most affected frequencies in the conventional pure-tone audiometry ranged from 3 to 6 kHz and, in the high-frequency audiometry, from 9000 to 11200 Hz. As for the transient otoacoustic emissions, the worse suppression effect results were found in the research group. CONCLUSION: There were differences among the hearing of family farmers and the control group. The conventional auditory thresholds are related to the group, age and sex. Farming is associated with impairments in the basal region of the cochlea, absence of acoustic reflex, reduced signal-to-noise ratio of the transient otoacoustic emissions, and dysfunction in the olivocochlear efferents of the auditory system.

OBJETIVO: Analisar as possíveis diferenças na audição de agricultores e suas famílias em comparação com população não exposta aos agrotóxicos. MÉTODO: Estudo transversal, com 70 participantes (grupo pesquisa), com média de idade de 39,7 anos, de ambos os sexos, proprietários de pequenos estabelecimentos agrícolas vinculados a agricultura familiar e tempo de exposição médio aos agrotóxicos de 23,7 anos. Um grupo controle com 71 participantes de ambos os sexos, sem exposição a ruído e agentes químicos, com idade média de 39,5 anos, foi incluído para a comparação dos resultados. Na etapa 1, ambos os grupos foram submetidos a audiometria convencional e de altas frequências e imitanciometria. Na etapa 2, somente os normoouvintes foram submetidos as emissões otoacústicas evocadas e efeito de supressão das emissões otoacústicas transientes. RESULTADOS: Observou-se diferenças significativas entre os grupos para audiometria tonal convencional e de altas frequências, e no reflexo acústico. As frequências mais afetadas na audiometria tonal convencional foram 3 a 6kHz e na audiometria de altas frequências foram as frequências de 9.000 e 11.200 Hz. Nas emissões otoacusticas transientes, observou-se no efeito de supressão piores resultados no grupo de pesquisa. CONCLUSÃO: Conclui-se que houve diferenças na audição dos agricultores familiares em comparação com o grupo controle. Os limiares auditivos convencionais estão relacionados em função do grupo, idade e gênero. O trabalho na agricultura está associado com o comprometimento na região basal da cóclea, à ausência de reflexo acústico, à redução da relação sinal/ruído das emissões otoacústicas transientes e à disfunção do sistema auditivo eferente olivococlear.

Hearing loss associated with xylene exposure in a laboratory worker.

BACKGROUND: Xylene is an organic solvent, widely used in histology laboratories and other occupational settings. Research in animals has demonstrated that xylene induces outer hair cell damage. Evidence regarding the effects of xylene in humans is only available from studies investigating workers exposed to mixtures of solvents containing xylene. These data indicate that mixtures of solvents containing xylene may induce hearing loss and central auditory dysfunction. PURPOSE: To comprehensively evaluate the peripheral and central auditory system of a histology laboratory worker exposed to xylene, who had presented with bilateral mild sensorineural hearing loss at an initial assessment. RESEARCH DESIGN: A case report of a male histology laboratory worker who has been exposed to xylene for over 20 yr. RESULTS: A diagnosis of bilateral mild sensorineural hearing loss of cochlear origin was made on the basis of otological, neuroimaging, and audiological examinations. Results indicating the absence of transient-evoked otoacoustic emissions, and auditory brainstem responses as expected for a mild cochlear hearing loss, were obtained. CONCLUSIONS: The observed bilateral mild sensorineural hearing loss was considered to have been induced by xylene exposure, due to the absence of any other etiological factors related to the onset of hearing loss. The results found in this patient are in agreement with animal data indicating xylene-induced ototoxicity. Xylene-exposed individuals should be audiologically monitored on a regular basis.