title: Modeling within- and across-channel processes in comodulation masking release.
abstract: The relative contributions of within-channel and across-channel processes to perceptual comodulation masking release (CMR) were investigated in the framework of an auditory processing model. A generalized version of the computational auditory signal processing and perception model [CASP; Jepsen et al., J. Acoust. Soc. Am. 124, 422-438 (2008)] was used and extended by an across-channel modulation processing stage according to Piechowiak et al. [J. Acoust. Soc. Am. 121, 2111-2126 (2007)]. Five experimental paradigms were considered: CMR with a broadband noise masker as a function of the masker spectrum level; CMR with four widely spaced flanking bands (FBs) varying in overall level; CMR with one FB varying in frequency and level relative to the on-frequency band (OFB); CMR with one FB varying in frequency; and CMR as a function of the number of FBs. The predictions suggest that at least three different mechanisms contribute to overall CMR in the considered conditions: (1) a within-channel process based on changes in the envelope characteristic due to the addition of the signal to the masker; (2) a within-channel process based on nonlinear peripheral processing of the OFB's envelope caused by the FB(s); and (3) an across-channel process that is robust across presentation levels but relatively small (2-5 dB).
authors.affiliation: Centre for Applied Hearing Research, Department of Electrical Engineering, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark. tdau@elektro.dtu.dk
authors.forename: Torsten
authors.initials: T
authors.lastname: Dau
authors.forename: Tobias
authors.initials: T
authors.lastname: Piechowiak
authors.forename: Stephan D
authors.initials: SD
authors.lastname: Ewert
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D000704:Analysis of Variance; D001299:Audiometry; D001307:Auditory Perception; D001309:Auditory Threshold; D003051:Cochlea / Q000502:physiology*; D003198:Computer Simulation; D005260:Female; D006801:Humans; D008297:Male; D008960:Models, Psychological; D009622:Noise / Q000009:adverse effects*; D017711:Nonlinear Dynamics; D010470:Perceptual Masking; D011571:Psychoacoustics; D013018:Sound Spectrography; D013997:Time Factors; D055815:Young Adult