The effect of impulse noise on cochlear vessels.

Short- and long-term changes in the cochlear vasculature and long-term changes in the sensorineuroepithelium were studied in guinea pigs after they were exposed to impulse noise. Vessel histology and cochlear hair cell loss were assessed, using a surface-preparation technique, and the results showed considerable variability. Hair cell loss and radial tears in the organ of Corti were a common finding in the animals killed four weeks after impulse-noise exposure. Impulse-noise exposure resulted in few cochlear vascular changes in the acutely and chronically affected groups. Compared with the results of our previous studies using continuous-noise exposure of different characteristics and in different mammals, this impulse-noise experiment resulted in a nonsignificant damaging effect on the cochlear vasculature.