Threshold shift dynamics following interrupted impact or continuous noise exposure: a review.
Davis-RI; Hamernik-RP; Ahroon-WA; Underwood-KA
Scientific basis of noise-induced hearing loss. Axelsson A, Borchgrevink HM, Hamernik RP, Hellstrom PA, Henderson D, Salvi RJ, eds. New York: Thieme Medical Publishers, Inc., 1996 May; :134-149
Over the last few years a number of experiments have confirmed the observations of Miller et al. that threshold shift (TS) in subjects given a brief daily noise exposure over several days could recover as much as 30 dB despite the continuing exposure cycle. This effect is now commonly referred to as a toughening effect. Another manifestation of toughening was demonstrated by Canlon et al. who showed that an exposure to a low level conditioning noise could reduce the permanent threshold shift (PTS) from subsequent high level exposure despite the absence of an effect from the conditioning exposure . While the experimental paradigms for these two experiments are quite different, the protective effects that they produce are thought to involve similar cochlear mechanisms. Interest in interrupted noise exposure paradigms was revived after Clark et al. confirmed the Miller et al. results. A small body of literature has emerged since then showing that interrupted exposures using broadband or narrowband, continuous or impulsive noise could elicit a cochlear toughening effect. These studies have involved the use of behavioral conditioning, brain stem evoked potentials, gross cochlear potentials, single VUl nerve recordings, and distortion product emissions to document the phenomena, This chapter reviews the existing body of data acquired from interrupted noise exposure paradigms.
Noise; Noise-exposure; Noise-measurement; Exposure-levels; Noise-analysis; Hearing-conservation; Threshold-limit-values; Noise-protection; Behavior; Behavior-patterns
Axelsson-A; Borchgrevink-HM; Hamernik-RP; Hellstrom-P-A; Henderson-D; Salvi-RJ
Scientific basis of noise-induced hearing loss
Plattsburgh State University, New York