"Comparison of auditory efferen pathway between learning disabled and normal students aged 7-10 years with suppression of otoacoustic emissions "

A common complaint of children with learning disability (LD) is difficulty in understanding speech in the presence of background noise. Evidence from animal and human studies has indicated that the medial olivocochlear bundle (MOCB) play a role in hearing in the presence of noise. The MOCB function can be evaluated by the suppression effect of the click evoked otoacoustic emission (CEOAEs) in response to contralateral white noise. The present study was conducted to compare the suppression effect of CEOAEs between LD and normal students. This research is an analytic-interventional study. The study group consisted of 20 learning disabled and 20 normal male students. The suppression effect of CEOAEs was evaluated by a comparison between CEOAEs levels in two conditions- with and without presentation of contralateral white noise. In the absence of noise there was no significant difference between CEOAEs amplitudes of two groups while there was significant difference between CEOAEs of two groups in the presence of noise. The suppression effect of CEOAEs in normal students had significant difference with LD students. The reduced suppression effect in LD students indicates the reduced activity of the MOCB function and efferent pathway in LD students which affect their ability to hear in the presence of background noise. Consequently, the suppression effect of CEOAEs can be used in the test battery approach of LD children.