Bekesy Audiometry and Temporal Summation

Abstract

The Bekesy Audiometer in its pulsed mode of operation customarily presents tones at a repetition rate of 2.5/sec with a duration of about 200 msec and a rise-fall time of 25 msec. The protocol developed for Threshold-Duration functions calls for tones with a repetition rate of 1/sec with a duration of 500 msec and a rise-fall time of 10 msec. This investigation compared the thresholds obtained with each of these types of signals to those obtained with a continuous tone at 250, 1000, and 4000 Hz. The results indicate that there are only slight differences between thresholds obtained with the tones provided by the conventional Bekesy Audiometer and the 500-msec tones used to obtain Threshold-Duration functions, at least during fixed-frequency tracings for normal-hearing listeners. When the thresholds for each of these pulsed tones are compared to those obtained with a continuous tone, however, clinically significant differences emerge.