THE EFFECT OF STIMULUS RATE ON THE CONTRALATERAL SUPPRESSION OF TRANSIENT EVOKED OTOACOUSTIC EMISSIONS

A new technique, which uses Maximum Length Sequences (MLSs) to enable the recording of TEOAEs at very fast rates, has been described previously. Such a technique enables rate studies to be carried out and here the effects of stimulus rate on the contralateral suppression of TEOAEs (Collet effect) have been studied. The results show that the Collet effect has virtually disappeared by a click stimulation rate of 2000 clicks/s. The waveform changes caused by the 'adaptation' due to increase in stimulus rate and the 'suppression' due to contralateral stimulation have been evaluated and compared. The comparison indicates that the same mechanism may be involved in both; the increase in stimulus rate leading to an ipsilateral suppression, greater in value but the same in form as the contralateral suppression.