EFFECT OF SIMULATED BILATERAL COCHLEAR DISTORTION ON SPEECH-DISCRIMINATION IN NORMAL SUBJECTS

Effect of simulated bilateral cochlear distortion on speech discrimination in normal subjects. Hood, J.D. and Prasher, D.K. (Medical Research Council Neuro-Otology Unit, Institute of Neurology, National Hospital, London, England). Scand Audiol 1990, 19 (37-41). Bilatera sensorineural hearing loss may introduce grossly dissimilar cochlear distortion at the two ears, causing abnormal demands to be made upon the cortical analytical centres which normally receive congruent information. As a result, the prescription of binaural hearing aids may be a handicap rather than a help. In order to explore this possibility, 10 normal subjects were presented with simulated, dissimilar cochlear distortion at the two ears. Discrimination scores with binaural presentation were poorer than the best monaural score and there were clear indications that in the former, subjects selectively attended to one ear and neglected the other. In contrast, binaural presentation of the same simulated distortion resulted in a significant improvement, compared with the monaural discrimination score. Inability of the cortex to contend with discongruent speech input from the two ears may be a factor contributing to the rejection of binaura hearing aids in some individuals. © 1990, Informa UK Ltd. All rights reserved.