Modeling comodulation masking release using an equalization-cancellation mechanism.
This study presents an auditory processing model that accounts for the perceptual phenomenon of comodulation masking release (CMR). The model includes an equalization-cancellation (EC) stage for the processing of activity across the audio-frequency axis. The EC process across frequency takes place at the output of a modulation filterbank assumed for each audio-frequency channel. The model was evaluated in three experimental conditions: (i) CMR with four widely spaced flanking bands in order to study pure across-channel processing, (ii) CMR with one flanking band varying in frequency in order to study the transition between conditions dominated by within-channel processing and those dominated by across-channel processing, and (iii) CMR obtained in the "classical" band-widening paradigm in order to study the role of across-channel processing in a condition which always includes within-channel processing. The simulations support the hypothesis that within-channel contributions to CMR can be as large as 15 dB. The across-channel process is robust but small (about 2-4 dB) and only observable at small masker bandwidths. Overall, the proposed model might provide an interesting framework for the analysis of fluctuating sounds in the auditory system.
Piechowiak
Tobias
T
Centre for Applied Hearing Research, Acoustic Technology, Ørsted DTU, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark.
Ewert
Stephan D
SD
Dau
Torsten
T
D000328:Adult; D001301:Audiometry, Pure-Tone / Q000379:methods*; D001489:Basilar Membrane / Q000502:physiology*; D007758:Ear, Inner / Q000502:physiology; D006801:Humans; D010470:Perceptual Masking / Q000502:physiology*; D017603:Signal Detection, Psychological