Year: 1981
Type: conference-abstract
Abstract: Groups of human subjects were exposed for 8 or 24 h to an octave-band noise centered at 63, 125, or 250 Hz. For a 24-h exposure at 84 dBA, temporary threshold shifts (TTS) increased for 8–12 h and then either decreased or remained constant. TTS was maximal in the frequency region between 350–700 Hz regardless of the center frequency of the exposure. Although TTS was less than 20 dB, complete recovery for many of the subjects required as long as 48 h. Accordingly, the higher level exposure which was planned at 94 dBA for 24 h was reduced to 90 dBA for 8 h. For this condition TTS increased throughout the 8-h exposure. TTS from the 90-dBA exposure for 8 h exceeded the TTS produced by the 24-h exposure at the 84 dBA. Whereas recovery from the 24-h exposure which produced TTS's of 15 dB required as long as 48 h, recovery from the 8-h exposure which produced TTS's of 20 dB required 12–24 h. Thus, the time required for recovery from TTS is determined in part by the duration of exposure. Nonauditory effects included small increases in serum cortisol only during the first hour of exposure. Heart rate, blood pressure, and catecholamines showed small changes. These changes and those of serum cortisol are difficult to interpret because of the absence of a completely counterbalanced design and the lack of rigorous control of the subjects' activity during the noise exposure. [Supported by NIEHS and DAMD.]
DOI: 10.1121/1.2018676
Authors: John H. Mills, J. David Osguthorpe, C. K. Burdick, J. H. Patterson, B. Mozo Osguthorpe
Language: English
Subfield: Sensory Systems
Field: Neuroscience
Domain: Life Sciences
Open Access status: bronze
OpenAlex ID: W1982047497