Masking of short probe sounds by tone bursts with a sweeping frequency

Abstract

The masked threshold of a short probe tone or a short one‐third octave probe noise appears to increase if the frequency of a tonal masker is swept. Frequency sweeps were exponential (octave/s) and unidirectional. Probe sounds were presented in the time center of the masker at the center frequency of the masker. The sweep gradient appeared to be an important parameter, masker duration was much less important. For 10‐ms probes, 100‐ms maskers, and upward sweeps increase of the masked threshold appeared to be maximal at a sweep gradient of 30 octave/s and the masked threshold was 21 dB higher than the masked threshold found for the steady masker (0 octave/s). Above 30 octave/s the masked threshold decreased. For downward sweeps masking was maximal at 20 octave/s and the threshold was 15 dB higher. The results are inconsistent with current models of masking: sweeping the frequency, the masked threshold increases whereas the energy within the critical band at the probe frequency decreases. [Research supported by the Netherlands Organization for the Advancement of Pure Research, ZWO.]