The effect of crossed olivo-cochlear bundle stimulation on acoustic trauma.

To investigate whether the crossed olivo-cochlear bundle (COCB) functions in a protective manner, albino guinea pigs were exposed to sounds of varying intensity (110-130 dB SPL, 3-30 min) with or without electric stimulation of COCB, and the threshold shifts of the compound action potential (CAP) were examined. A statistically significant protective effect was observed in animals exposed to stimuli of intermediate intensity which induce threshold shifts of 50 to 55 dB on average. No protective effect was observed in the groups exposed to greater or milder stimuli. These results are discussed in the light of the available literature.