Impulse noise induced damage in the vestibular end organs of the guinea pig. A light microscopic study.

Guinea pigs were exposed to the impulse noise from 90-300 rifle shots (peak 158 dB SPL, maximal energy content at 1.1 kHz). This exposure induced severe cochlear damage. The vestibular end organs also showed damage of varying degree. The ampullary cristae were most severely damaged, but changes were also seen in the utricular and saccular maculae. The changes appear to be primarily mechanical and to result from the effect of the acoustic pressure wave on the vestibular labyrinth.