Practical Gammatone-Like Filters for Auditory Modeling
Venue
EURASIP Journal on Audio, Speech, and Music Processing, vol. 2007 (2007), pp. 12
Publication Year
2007
Authors
Andreas G. Katsiamis, Emmanuel M. Drakakis, Richard F. Lyon
BibTeX
Abstract
This paper deals with continuous-time filter transfer functions that resemble
tuning curves at particular set of places on the basilar membrane of the biological
cochlea and that are suitable for practical VLSI implementations. The resulting
filters can be used in a filterbank architecture to realize cochlea implants or
auditory processors of increased biorealism. To put the reader into context, the
paper starts with a short review on the gammatone filter and then exposes two of
its variants, namely, the differentiated all-pole gammatone filter (DAPGF) and
one-zero gammatone filter (OZGF), filter responses that provide a robust foundation
for modeling cochlea transfer functions. The DAPGF and OZGF responses are
attractive because they exhibit certain characteristics suitable for modeling a
variety of auditory data: level-dependent gain, linear tail for frequencies well
below the center frequency, asymmetry, and so forth. In addition, their form
suggests their implementation by means of cascades of N identical two-pole systems
which render them as excellent candidates for efficient analog or digital VLSI
realizations. We provide results that shed light on their char- acteristics and
attributes and which can also serve as “design curves” for fitting these responses
to frequency-domain physiological data. The DAPGF and OZGF responses are
essentially a “missing link” between physiological, electrical, and mechanical
models for auditory filtering.
