Noise-induced hearing loss from non-Gaussian equal energy exposures.
Davis-RI; Qiu-W; Hamernik-RP
J Acoust Soc Am 2006 Nov; 120(5)(Part 2):3128-3129
Data from several different exposures showed that, for equivalent energy [Leq =100 dB9A)] and spectra, exposure to a continuous, non-Gaussian (nonG) noise produces greater hearing and sensory cell loss in the chinchilla than a Gaussian (G)noise. The statistical metric, kurtosis, could order the extent of the trauma. We extend these results to Leq=90 and 110 dB(A), non-Gaussian noises generated using broadband noise bursts, and bandlimited impacts within a continuous G background noise. Data from nine new experimental groups with 11 or 12 chinchillas/group will be presented. Evoked response audiometry established hearing thresholds and surface preparation histology quantified sensory cell loss. There were clear intensity-related effects. At the lowest levels there were no differences in the trauma produced by G and nonG exposures. At Leq=90 dB(A) nonG exposures produced increased trauma relative to equivalent G exposures. By removing energy from the impulsive transients by limiting their bandwidth, trauma could be reduced. The use of noise bursts to produce the nonG noise also reduced the amount of trauma. A metric based on kurtosis and energy may be useful in modifying existing exposure criteria.
Noise-exposure; Noise-induced-hearing-loss; Hearing-loss; Hearing-impairment; Animal-studies; Laboratory-animals; Exposure-assessment; Exposure-levels
Wei Qiu, PhD, Auditory Research Laboratory, State University of New York at Plattsburgh, 101 Broad Street, Plattsburgh, New York, 12901
Abstract; Conference/Symposia Proceedings
Disease and Injury: Hearing Loss
Journal of the Acoustical Society of America