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Occupational noise and age : a longitudinal study of hearing sensitivity

Dissertation (MCommunication Pathology)--University of Pretoria, 2018.

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Other Authors: Swanepoel, De Wet
Format: Thesis
Language:English
Published: University of Pretoria 2019
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access_status_str Open Access
author2 Swanepoel, De Wet
author_browse Swanepoel, De Wet
author_facet Swanepoel, De Wet
collection Thesis
dc_rights_str_mv © 2019 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria.
description Dissertation (MCommunication Pathology)--University of Pretoria, 2018.
format Thesis
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institution University of Pretoria (South Africa)
language English
last_indexed 2026-06-10T12:36:49.885Z
license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository
publishDate 2019
publishDateRange 2019
publishDateSort 2019
publisher University of Pretoria
publisherStr University of Pretoria
record_format dspace
source_str UPSpace — University of Pretoria Institutional Repository
spelling oai:repository.up.ac.za:2263/70582 Occupational noise and age : a longitudinal study of hearing sensitivity Swanepoel, De Wet leonijordaan@gmail.com Strauss, Susan Grobler, Leoni Margaretha UCTD Dissertation (MCommunication Pathology)--University of Pretoria, 2018. The interaction between age and noise and their individual effects on hearing is complex, making it difficult to distinguish between noise-induced hearing loss and agerelated hearing loss at an individual level. This retrospective cohort study aimed to determine the decline in hearing sensitivity in noise-exposed mineworkers as opposed to non-noise-exposed mineworkers over time to evaluate the combined and individual contributions of noise exposure and age. A mixed effects regression analysis was applied to longitudinal audiological data from a group of mineworkers in South Africa. Four serial (annual) audiograms of 2,583 mineworkers were utilised. Data of a non-noise-exposed group (n=951) and a group exposed to underground noise (≥85 dBA) (n=1632) were included. Results indicated that base values were significantly higher for the noise-exposed versus non-noise-exposed group, for the low-frequency average (LFA) of 0.5, 1 and 2 KHz (16.1 dB HL versus 11.1 dB HL), and high-frequency average (HFA) of 3, 4 and 6 KHz (25.7 dB HL versus 18.5 dB HL). These results may be indicative of previous noise damage in the noise-exposed group obtained before occupational noise limitations and personal hearing protection use were enforced through legislation in 2001. All year-to-year increases in mean hearing thresholds were statistically significant (p-values of <0.01). When correcting for age, year-to-year increases in mean hearing thresholds were higher for the noise-exposed group than for the nonnoise- exposed group when comparing HFA (3.5 dB versus 2.9 dB decline over a fouryear period) but similar when comparing LFA (0.6 dB versus 0.7dB decline over a fouryear period). Mixed effects regression analyses were repeated without correcting for age to represent year-to-year increases in hearing thresholds including noise and age influences. Year-to-year increases in mean hearing thresholds were significantly higher for the noise-exposed group than for the non-noise-exposed group in comparing HFA (4.0 dB versus 3.5 dB decline over a four-year period), and when comparing LFA (1.5 dB versus 1.1 dB decline over a four-year period). Year-to-year increases in mean hearing thresholds were between 0.4 and 0.9 dB higher in the analysis where age was uncorrected for, for both exposure groups across LFA and HFA, identifying age as a factor in year-to-year decrease in mean hearing thresholds. It is evident that occupational noise exposure and aging are significant contributors to hearing loss over time for mineworkers, even in a setting where noise exposure is controlled through legislation, and use of personal hearing protection is enforced. Ongoing effort is necessary to increase the effectiveness of noise management programmes in order to counter the prevailing negative effects of noise exposure on hearing thresholds, as well as the possible additive interaction between noise exposure and age-related hearing loss. Speech-Language Pathology and Audiology MCommunication Pathology Unrestricted 2019-07-08T09:46:55Z 2019-07-08T09:46:55Z 2019/04/10 2018 Dissertation Grobler, LM 2018, Occupational noise and age : a longitudinal study of hearing sensitivity, MCommunication Pathology Dissertation, University of Pretoria, Pretoria, viewed yymmdd <http://hdl.handle.net/2263/70582> A2019 http://hdl.handle.net/2263/70582 en © 2019 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria
spellingShingle UCTD
Occupational noise and age : a longitudinal study of hearing sensitivity
title Occupational noise and age : a longitudinal study of hearing sensitivity
title_full Occupational noise and age : a longitudinal study of hearing sensitivity
title_fullStr Occupational noise and age : a longitudinal study of hearing sensitivity
title_full_unstemmed Occupational noise and age : a longitudinal study of hearing sensitivity
title_short Occupational noise and age : a longitudinal study of hearing sensitivity
title_sort occupational noise and age a longitudinal study of hearing sensitivity
topic UCTD
url http://hdl.handle.net/2263/70582