Pure-Tone Octave Masking in Normal-Hearing Listeners

Octave masking in normal‐hearing listeners was investigated at four different primary masker frequencies (250, 500, 1000, and 2000 Hz) as a function of intensity and phase. Slopes of phase‐locked octave masking functions were found to increase with frequency of the primary masker, from less than 1.0 dB/dB at 250 Hz to greater than 3.0 dB/dB at 2000 Hz. The monaural octave masking phase effect was considerably larger at low primary frequencies (as large as 30 dB) than at high primary frequencies (no larger than 15 dB), and the phase effect decreased or disappeared entirely at intense primaries. Maximum and minimum masking were found at phase angles of 90° and 270°, respectively, irrespective of frequency and intensity of the primary masker. Implications of these results about distortion in the auditory system are discussed.