Simple Békésy-type audiometer for clinical use

A simple self-administering audiometer is described that presents a pure tone whose frequency automatically increases from 20 Hz to 20 kHz and whose intensity automatically decreases or increases (according to whether or not the subject is pressing a button) between -20 and 80 dB (ANSI 1969) normal range. The rates at which frequency and intensity vary may be preset over continuously adjustable ranges, 0-5 octaves/min and 0-24 dB/S, respectively.