Auditory filter shapes in forward masking as a function of level.

Thresholds were measured for 1-kHz, 5-ms sinusoidal signals following noise maskers with a spectral notch of variable width centered at 1 kHz. In one set of conditions threshold was measured as a function of notch width for three fixed noise levels: 30, 40, and 50 dB SPL/Hz. In order to compensate for the decay of masking, each signal threshold was transformed to the level of a flat-spectrum noise which would give the same masking effect. In a second set of conditions the noise level required for threshold was measured as a function of notch width for three fixed signal levels, separated by 5 dB. The auditory filters derived from the data were essentially the same for the two sets of conditions, and did not vary significantly with masker or signal level. The filters had a mean 3-dB bandwidth of 90 Hz.