Effects of Reverberant Impulse Noise (BLAST WAVES) on Hearing: Parametric Studies

摘要

This research is directed at studying the effects on the auditory system ofexposure to high levels of reverberant impulse noise using an animal (chinchilla) model. The blast waves were generated by a three inch diameter shock tube (source III), which produced wave signatures having spectral energy concentrated in the 12 kHz region. The waves were discharged into a reverberant chamber within which animals were individually exposed. Animals were exposed to either 150, 155 or 160 dB peak SPL impulses. The number of impulses presented at each intensity was 1, 10 or 100, with repetition rates fixed at 1 impulse/sec. This parametric design yielded 9 groups of animals. There were 15 animals in each group. Brainstem evoked potentials were used to estimate temporary and permanent threshold shifts and conventional surface preparations of the cochlea were used to quantitatively assess sensory cell loss. This midterm report presents the audiometric data and a portion of the histological data for the 136 animals that completed the exposure protocol. The audiometric and available histological data showed that damage to the auditory system systematically increased as the energy of the exposure was increased through manipulation of number of presentations or peak SPL. Hearing loss, Impulse noise, Blast waves, RADIII.