Post-masking decreases when a second masker suppresses audible masker fluctuations

Evidence

The examples indicated in Fig. 4.40 show the most pronounced effect. The data indicate that this astonishing effect may depend on the time structure of masker Ml, which produces a pronounced temporal pattern for narrow bandwidth below 600 Hz. Therefore, a model describing these results must be based on spectral and temporal features of the two maskers so that the distinctly audible fluctuations produced for a narrow-band masker Ml are taken into account. These fluctuations are strongly reduced when a second masker M2, a pure tone or a white noise is added. Consequently, in addition to the spectral effect, a pronounced temporal effect leading to a reduction of audible fluctuations is introduced, which finally produces a decrease of post-masked threshold by as much as 13 to 24 dB. The latter effect depends strongly on the masker’s bandwidth. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 633

The data indicate that this astonishing effect may depend on the time structure of masker Ml, which produces a pronounced temporal pattern for narrow bandwidth below 600 Hz. Therefore, a model describing these results must be based on spectral and temporal features of the two maskers so that the distinctly audible fluctuations produced for a narrow-band masker Ml are taken into account. These fluctuations are strongly reduced when a second masker M2, a pure tone or a white noise is added. Consequently, in addition to the spectral effect, a pronounced temporal effect leading to a reduction of audible fluctuations is introduced, which finally produces a decrease of post-masked threshold by as much as 13 to 24 dB. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 633

Categorization

• DEFINE: Explains the mechanism: adding a second masker removes audible temporal fluctuation of a narrow-band masker, which lowers post-masked threshold by 13-24 dB.
• corroborated: 2 independent passages support this claim — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 633