Modeling Pitch Perception With an Active Auditory Model Extended by Octopus Cells

Abstract

Pitch is an essential category for musical sensations. Models of pitch perception are vividly discussed up to date. Most of them rely on definitions of mathematical methods in the spectral or temporal domain. Our proposed pitch perception model is composed of an active auditory model extended by octopus cells. The active auditory model is the same as used in the Stimulation based on Auditory Modeling (SAM), a successful cochlear implant sound processing strategy extended here by modeling the functional behavior of the octopus cells in the ventral cochlear nucleus and by modeling their connections to the auditory nerve fibers (ANFs). The neurophysiological parameterization of the extended model is fully described in the time domain. The model is based on latency-phase en- and decoding as octopus cells are latency-phase rectifiers in their local receptive fields. Pitch is ubiquitously represented by cascaded firing sweeps of octopus cells. Based on the firing patterns of octopus cells, inter-spike interval histograms can be aggregated, in which the place of the global maximum is assumed to encode the pitch.

Periodicity Pitch Perception

“…We like to show a bio-plausible way of F0 estimation as a possible starting point for novel research. As a prerequisite, auditory models of pitch perception have been created, implemented, and discussed (Patterson et al, 2002;Laudanski et al, 2014;Langner, 2015;Stolzenburg, 2015;Ahmad et al, 2016;Joris, 2016;McLachlan, 2016;Barzelay et al, 2017;Friedrichs et al, 2017;Saeedi et al, 2017;Tang et al, 2017;Todd et al, 2017;Harczos and Klefenz, 2018;Oxenham, 2018;Peng et al, 2018).…”

“…Octopus cells latency-phase rectify space-time trajectories in their TRFs (Golding and Oertel, 2012;McGinley et al, 2012). Octopus cells rhythmically spike with the pitch periodicity of the sound because they decode repetitively occurring latency-phase trajectories (Harczos and Klefenz, 2018).…”

“…For the bio-physical modeling part of the extended SAM front-end, we kindly refer to our previous open access paper (Harczos and Klefenz, 2018), the mathematical notation and symbols of which we continue using throughout the rest of this paper.…”

“…Bottom: Action potentials of the spiral ganglion neurons (SGN). Note that the ordinate shows the characteristic frequency of the basilar membrane model at the corresponding cochlear position (Reprint from Harczos and Klefenz, 2018).…”

“…Our self-developed ANF spike from audio generation program SAM is used as audio front end (Harczos et al, 2013a). We recently extended SAM by model octopus cells innervated by ANFs (Harczos and Klefenz, 2018). These models are shortly summarized for better comprehensibility in see section "Materials and Methods."…”