Some vascular effects of noise exposure in the chinchilla cochlea.

Chinchillas were exposed to pink noise at levels ranging from 110 dB (for 8 h) to 125 dB (for 1/4 h). After a 3-week survival period, the animals were terminated without anesthesia and tissues were prepared using a soft-surface preparation technique [Axelsson et al., Acta Otolaryngol. 80, 362 (1975)]. Cochlear hair cell damage as well as vascular pathology was slight. On occasion, a vessel or vessel segment was obviously atypical, thus allowing noise-exposed animals to be differentiated from their non-noise-exposed controls. More often, however, differences between animals were more discrete and only evident through a computer analysis of the data. The specific effects of these particular noise-exposure parameters on the cochlear blood supply of the chinchilla will be discussed.