Function-based modeling of binaural processing: level and time cues.
From theoretical considerations, function-based modeling predicts the input-output characteristics of a neural system intended to perform a signal processing task within a sensory system. The sensory task under study here is the time- and level-based localization of a high-frequency, possibly amplitude-modulated, sound source in the horizontal plane. The stimulus is assumed to be represented by each ear's primary-like discharge pattern. An optimal system that extracts azimuthal angle from these discharge patterns, which represent acoustic time and level localization cues, has been derived. This system can be described as the maximization of a sum of three subsystems' outputs. The stimulus cues employed by these systems are interaural level difference for the level-based subsystem, the interaural onset-time difference for the time-based subsystem, and the interaural envelope-phase difference for the phase-based subsystem. The system encompassing all these cues is shown to trade-off the level, time, and envelope-phase cues depending upon the time since stimulus onset, the observation time, and the incident signal's level. How this system might correspond to known structures in the lower auditory pathway is described.
Dabak
A G
AG
Department of Electrical & Computer Engineering, Rice University, Houston, Texas 77251-1892.
Johnson
D H
DH
D000161:Acoustic Stimulation; D000162:Acoustics; D001306:Auditory Pathways / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology*; D001309:Auditory Threshold; D005260:Female; D006801:Humans; D008297:Male; D008962:Models, Theoretical; D011601:Psychophysics; D013017:Sound Localization / Q000502:physiology*