HEARING FACULTY TESTING

Hearing faculty test apparatus, for use in relation to the inner ear by way of the so-called cochlear echo, repeatedly applied a linearly balanced set of acoustic stimuli to the ear, individually sums each related set of responses to the stimuli set, interrogates each sum to detect components above a predetermined threshold, and averages sums on a selective basis depend on the interrogation. Preferably sums are passed for averaging only when whooly within the threshold. Also, averaging is preferably by use of two like averagers to which accepted sums are applied in alternating manner, with the two averages being fed to a correlator.