Cochlear blood flow. Effect of noise.

Cochlear blood flow as investigated in anesthetized gerbils exposed to high-frequency (10 to 40 kHz), high-intensity (113 dB sound pressure level noise for 13 minutes. Blood flow was measured using a newly developed technique, which combines the surface preparation dissecting of the cochlea with the microsphere method. Our experiments indicate that short-lasting, high-intensity noise exposure causes a highly significant elevation of the blood flow in noise-exposed inner-ear areas. On the exposed side, blood flow increase was observed in the first turn of the stria vascularis-supralis ossea. On the opposite side, which was exposed only through bone conduction, blood flow was significantly elevated only in the basilar membrane.