ON LATERAL INHIBITION IN THE AUDITORY-SYSTEM

Suga (1994) has presented arguments supporting the existence of latera l inhibition in the auditory system. We developed a computational mode l of a lateral inhibition neural network possibly taking part in audit ory stimulus processing. The behavior of the model under several hypot hetical auditory stimuli matches experimental results. We have shown t hat lateral inhibition can be the cause of tinnitus in some conditions . 95% of subjects have phantom perceptions in the absence of auditory stimulation (acoustically shielded chambers). We suggest that the spon taneous activity in the auditory nerve (a Poisson-like neural noise), processed by lateral inhibition, is responsible for this phenomenon. A ctivity is generated in the output layer of the network under stimulat ion with a Poisson-like noise. In the presence of acoustic stimulation this neural noise is masked by the stimulus or the ambient wideband a coustic noise. The wideband noise is effectively suppressed in lateral inhibition. The shape of the probability density function of the nois e determines whether it will be effectively suppressed. The edge effec t has been demonstrated to be also a possible consequence of lateral i nhibition.