Occupational and Environmental Medicine · 2001 · 249 citations · 17 references
Health ProfessionsAudiologyOtolaryngologyHearing AssessmentHearing ConservationHearing ScienceHearing ImpairmentHearing LossNoiseNoise ExposureNoise-induced Hearing DamageOccupational Noise ExposureAudiometric NotchingConfidence Intervals For Odds RatiosContinuous Noise EffectsHearing Conservation AssessmentImpulse NoiseImpulse Noise ExposureLogistic RegressionOccupational Noise Exposure Assessment
The 6 kHz audiometric notch is variable and not linked to noise exposure, whereas the 4 kHz notch remains a well‑established clinical sign of NIHL. The study aimed to examine how different noise exposures relate to the audiometric notch, a classic indicator of noise‑induced hearing loss, in electrical transmission workers. Audiograms from a hearing‑conservation program were independently reviewed by three clinicians to identify notches, while a questionnaire gathered exposure histories and logistic regression was used to estimate odds ratios for risk factors. Among 357 respondents, 49 % had a notch, yet only 4 kHz notches showed a significant association with firearms exposure (OR 4.25), whereas 6 kHz notches were unrelated to the assessed risk factors.
To investigate the relation between different types of exposure to noise and a classic sign of noise induced hearing loss (NIHL), the audiometric notch.The study sample had exposure to both continuous and impulse noise and was drawn from a population of electrical transmission workers. Audiograms, taken as part of a hearing conservation programme, were read by three clinicians experienced in the assessment of NIHL. Working independently and using their clinical judgment, they were asked to identify localised increases in the threshold of hearing (audiometric notches) which they would attribute to noise, had a suitable history of exposure been elicited. Prevalent cases of NIHL were identified by the presence of a notch in either ear. Risk factors for NIHL were assessed by a questionnaire which sought information about exposure to air blast circuit breaker noise; firearms; explosions, and continuous noise. The odds of exposure to these factors in those with and without hearing loss were calculated, and odds ratios (ORs) and 95% confidence intervals (95% CIs) were estimated by logistic regression.Of the 648 questionnaires sent out 357 were returned, a response rate of 55%. Of these, at least two out of the three assessors identified 175 (49%) people with a notch at any audiometric frequency. There was no association between these cases and the NIHL risk factors identified by the questionnaire, but a further frequency specific analysis showed a small proportion of people (15 (4%)) with notches at 4 kHz who had the expected associations with exposure to noise and a significant OR for firearms of 4.25 (95% CI 1.28 to 14.1). The much larger proportion of people with 6 kHz notches (110 (31%)) did not show these associations.To diagnose NIHL it is important to elicit a detailed and accurate history of exposure to noise: although the notch at 4 kHz is a well established clinical sign and may be valuable in confirming the diagnosis, the 6 kHz notch is variable and of limited importance.
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Peter Rabinowitz · 2000 · 604 citations
Applied Ergonomics · 1971 · 209 citations
Study of Noise and Hearing in Jute Weaving
W. Taylor, Jennifer Pearson, A. Mair et al. · The Journal of the Acoustical Society of America · 1965 · 183 citations
Hazardous Exposure to Impulse Noise
R. R. A. Coles, Georges R. Garinther, David C. Hodge et al. · The Journal of the Acoustical Society of America · 1968 · 121 citations
Early Noise-induced Hearing Loss in Teenage Boys
A. Axelsson, Tomas Jerson, Ulla-Beth Lindberg et al. · Scandinavian Audiology · 1981 · 81 citations