Pure-Tone Octave Masking in Normal-Hearing Listeners

Abstract

Octave masking was investigated at four different frequencies (250, 500, 1000, and 2000 Hz) as a function of intensity of the masker and phase of the test signal. Slopes of phase-locked octave masking were found to increase with masking signal frequency, from 0.80 dB/dB at 250 Hz to 3.0 dB/dB at 2000 Hz. The monaural octave-masking phase effect was considerably larger for masking signals at low frequencies than at high frequencies, and the phase effect decreased or disappeared entirely for high-level masking signals. Interpretations are considered which take recent neurophysiological and physiological data into account, and which describe the octave-masking phase effects in terms of temporal pattern discrimination. Those interpretations adequately account for the frequency dependencies found in octave-masking phase effects.