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

Abstract

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.

Achados audiológicos de frentistas expostos a combustíveis

“…Previous studies have brought up the need for guidance for clinical audiologists regarding the selection of tests to be used in the evaluation of patients with a history of exposure to ototoxic chemicals 15,18 . Differences between mean group results were detected when test results were classified for normality.…”

“…At this time, there is no consensus as to which tests should be part of the audiological assessment of populations exposed to ototoxicants at work. Several audiological tests have been examined for this particular use [14][15][16][17][18] . The present study used an extensive battery of tests to evaluate the peripheral and central auditory systems of gas station attendants exposed to fuel.…”

Preventing Occupational Hearing Loss: 50 Years of Research and Recommendations from the National Institute for Occupational Safety and Health

“…11 An updated summary of occupational ototoxicity is being published concurrently in this issue of Seminars in Hearing. 179 In 2018, NIOSH collaborated with OSHA to publish a short summary document on ototoxicity. The joint information bulletin, Preventing Hearing Loss Caused by Chemical (Ototoxicity) and Noise Exposure, describes the effects that chemicals can have on hearing, identifies chemicals which are ototoxic, provides examples of industries and occupations in which these exposures might be found, and makes recommendations for prevention.…”

“…11 An updated summary of occupational ototoxicity is being published concurrently in this issue of Seminars in Hearing . 179 …”