High‐ and Low‐Frequency Loudness Adaptation

Recent literature [Stockinger and Studebaker, (1968) and Petty, Fraser, and Elliott (1970)] contradicts much of the preexisting data concerning the magnitude and time course of suprathreshold loudness adaptation. A detailed study was undertaken to determine the magnitude of suprathreshold adaptation at 500 and 3000 Hz in six normal‐hearing subjects. A controlled period of preadaptation was followed by 7 min of a continuous adapting signal of 70 dB SPL in one ear. The adapting tone was then continued an additional 4 min while a pulsed tone, identical to the pre‐adapting conditions (3000 msec, 331/3% duty cycle, 10 msec rise‐decay time) was introduced into the comparison ear for perstimulatory dichotic loudness balances. The experimental conditions were (1) adapting tone: 500 Hz; comparison tone: 400 or 3000 Hz; (2) adapting tone: 3000 Hz; comparison tone: 500 or 2000 Hz. Under these heterophonic conditions, adaptation was measured by the method of constant stimuli and repeated with a linear tracking techni...