Portland State University. Department of Speech Communication.
Thomas G. Dolan
Date of Publication
Master of Science (M.S.) in Speech Communication
Noise -- Physiological effect -- Measurement, Industrial noise -- Physiological effect -- Measurement, Hearing aids
1 online resource (2, vi, 82 p.)
Federal regulations specify that an employee working for eight hours cannot legally be exposed to noise which has a time-weighted average greater than 90 decibels on the A scale. The industrial workforce is comprised of not only people with normal hearing acuity, but of individuals who suffer from hearing loss. While current noise regulation standards are deemed appropriate for those with normal hearing, it is difficult to apply these standards to persons wearing hearing aids on the job. The ambient, or unamplified, noise levels that fall below the maximum permitted by OSHA standards may very well be amplified to levels greater than 90 dBA, by the hearing aid. If this were the case, the company employing the hearing aid user would technically be in violation of the OSHA regulations. This study addressed the question of what noise exposure might be expected for hearing aid users on the job in different situations, as well as in non-vocational settings. The research involved two methods, conducted to determine the noise levels created by hearing aids with different amounts of gain and to determine whether the amplified noise levels exceed those requiring intervention under current regulations. For both methods, ambient and amplified noise levels for each condition were gathered in specified increments, and were compared with regard to current regulatory standards. The resultant data revealed that when ambient noise levels average between 80 and 84 dBA, amplification provided by even a mild gain hearing aid caused the eight hour time-weighted averages (TWA's) to increase to levels above the 90 dBA maximum permissible levels as delineated by OSHA. Moderate and high gain aids further increased these levels. The results of this study suggest that the hearing aid users in industrial and perhaps non-industrial settings may very well be exposed to intensity levels which exceed OSHA maximums, even when ambient levels do not. The extent to which these arc exceeded are based on the gain and output of the hearing aid in use.
O'Connor, Jody Lynn, "A Comparison of Ambient and Hearing Aid Output Noise Levels in Industrial and Non-industrial Settings" (1993). Dissertations and Theses. Paper 5147.