PERIPHERAL AUDITORY LATERALIZATION ASSESSMENT USING TEOAES

Previous studies indicate a left-right asymmetry in the function of pe ripheral auditory system. Contralateral acoustic suppression of TEOAEs (transient evoked otoacoustic emissions) enables assessment of medial olivocochlear efferent system functioning, and has demonstrated that this system is more effective in the right than in the left ear. Moreo ver, TEOAE amplitudes are lower in the left than in the right ear. The aim of the present experiment was to verify firstly the absence of a relationship between medial efferent system asymmetry and TEOAE amplit ude asymmetry, and secondly to study TEOAE input/output function slope s. There was no link between the asymmetries in TEOAE amplitude and in the medial efferent system functioning. Further, as previously shown, the medial olivocochlear system increased the TEOAE input/output func tion slopes. These TEOAE input/output function slopes seem to be consi stent factors in peripheral asymmetry since the slope is lower in the right than in the left ear. Moreover, the lower the TEOAE amplitudes, the greater the TEOAE slopes. The slope asymmetry of the two ears coul d correspond to earlier saturation or a lower augmentation ability of the TEOAE response in the right ear, where the TEOAE amplitude is high er. This asymmetry in growth slopes reinforces the notion of periphera l auditory lateralization. (C) 1998 Elsevier Science B.V. All rights r eserved.