Modulation masking produced by second-order modulators.

Christian Füllgrabe; Brian C J Moore; Laurent Demany; Stephan D Ewert; Stanley Sheft; Christian Lorenzi

doi:10.1121/1.1861892

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PubMed · 15898657

Modulation masking produced by second-order modulators.

Christian Füllgrabe·Brian C J Moore·Laurent Demany·Stephan D Ewert·Stanley Sheft·Christian Lorenzi

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Abstract

Recent studies suggest that an auditory nonlinearity converts second-order sinusoidal amplitude modulation (SAM) (i.e., modulation of SAM depth) into a first-order SAM component, which contributes to the perception of second-order SAM. However, conversion may also occur in other ways such as cochlear filtering. The present experiments explored the source of the first-order SAM component by investigating the ability to detect a 5-Hz, first-order SAM probe in the presence of a second-order SAM masker beating at the probe frequency. Detection performance was measured as a function of masker-carrier modulation frequency, phase relationship between the probe and masker modulator, and probe modulation depth. In experiment 1, the carrier was a 5-kHz sinusoid presented either alone or within a notched-noise masker in order to restrict off-frequency listening. In experiment 2, the carrier was a white noise. The data obtained in both carrier conditions are consistent with the existence of a modulation distortion component. However, the phase yielding poorest detection performance varied across experimental conditions between 0 degrees and 180 degrees, confirming that, in addition to nonlinear mechanisms, cochlear filtering and off-frequency listening play a role in second-order SAM perception. The estimated magnitude of the modulation distortion component ranges from 5%-12%.

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Adolescent Adult Cochlea Computer Graphics Filtration Hair Cells, Auditory, Outer Humans Noise Nonlinear Dynamics Perceptual Distortion Perceptual Masking Pitch Discrimination Psychoacoustics Sound Spectrography Time Perception Journal Article Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, P.H.S.

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Christian Füllgrabe, Brian C J Moore, Laurent Demany, Stephan D Ewert, Stanley Sheft, Christian Lorenzi. 2005. Modulation masking produced by second-order modulators.. https://doi.org/10.1121/1.1861892

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