COMPUTER-AIDED HEARING THRESHOLD DETERMINATION FROM CORTICAL AUDITORY-EVOKED POTENTIALS

The determination of the hearing threshold from cortical electric resp onses is usually based on the visual inspection of the recordings by a n experienced evaluator. At least two factors are responsible for the limited reliability of such a procedure: first, visual inspection yiel ds the response threshold and not the hearing threshold; and second, t he result of a visual evaluation depends on subjective appraisal, whic h may be influenced by irrational factors. An approach of computer-aid ed evaluation is presented which simulates the visual inspection in th at several typical features of the curves are judged numerically. The result of the classification is a single parameter, Q, whose value inc reases with better (subjective) perceptibility of the evoked potential s. A statistical analysis explores the relationship between the value of Q and the psychophysical hearing threshold. The results show that a prediction of hearing threshold with an accuracy of +/- 10 dB is poss ible.