Document Type
Article
Publication Date
2-1-2024
Publication Title
Designs
Volume
8
Issue
1
Keywords
basilar membrane, clarion processor, cochlear implant, equivalent rectangular bandwidth (ERB), gammatone filter (GTF) bank, pseudo-resonant frequency
Abstract
Commercially available cochlear implants are designed to aid profoundly deaf people in understanding speech and environmental sounds. A typical cochlear implant uses a bank of bandpass filters to decompose an audio signal into a set of dynamic signals. These filters’ critical center frequencies (Formula presented.) imitate the human cochlea’s vibration patterns caused by audio signals. Gammatone filters (GTFs), with two unique characteristics: (a) an appropriate “pseudo resonant” frequency transfer function, mimicking the human cochlea, and (b) realizing efficient hardware implementation, could demonstrate them as unique candidates for cochlear implant design. Although GTFs have recently attracted considerable attention from researchers, a comprehensive exposition of GTFs is still absent in the literature. This paper starts by enumerating the impulse response of GTFs. Then, the magnitude spectrum, (Formula presented.), and bandwidth, more specifically, the equivalent rectangular bandwidth (ERB) of GTFs, are derived. The simulation results suggested that optimally chosen filter parameters, e.g., critical center frequencies, (Formula presented.) ; temporal decay parameter, (Formula presented.) ; and order of the filter, (Formula presented.), can minimize the interference of the filter bank frequencies and very likely model the filter bandwidth (ERB), independent of (Formula presented.). Finally, these optimized filters are applied to delineate a filter bank for a cochlear implant design based on the Clarion processor model.
DOI
10.3390/designs8010016
E-ISSN
24119660
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Recommended Citation
Islam, Rumana and Tarique, Mohammed. (2024). Investigating the Performance of Gammatone Filters and Their Applicability to Design Cochlear Implant Processing System. Designs, 8 (1).
https://scholar.uwindsor.ca/electricalengpub/484