Investigating the Performance of Gammatone Filters and Their Applicability to Design Cochlear Implant Processing System
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 <...
| Main Authors: | , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2024-02-01
|
| Series: | Designs |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2411-9660/8/1/16 |
| _version_ | 1827343784529100800 |
|---|---|
| author | Rumana Islam Mohammed Tarique |
| author_facet | Rumana Islam Mohammed Tarique |
| author_sort | Rumana Islam |
| collection | DOAJ |
| description | 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 <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi>f</mi></mrow><mrow><mn>0</mn></mrow></msub></mrow></semantics></math></inline-formula> 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, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>|</mo><mi>H</mi><mo>(</mo><mi>f</mi><mo>)</mo><mo>|</mo></mrow></semantics></math></inline-formula>, 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,<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi>f</mi></mrow><mrow><mn>0</mn></mrow></msub></mrow></semantics></math></inline-formula>; temporal decay parameter, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>b</mi></mrow></semantics></math></inline-formula>; and order of the filter, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>n</mi></mrow></semantics></math></inline-formula>, can minimize the interference of the filter bank frequencies and very likely model the filter bandwidth (ERB), independent of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mfrac><mrow><msub><mrow><mi>f</mi></mrow><mrow><mn>0</mn></mrow></msub></mrow><mrow><mi>b</mi></mrow></mfrac></mrow></semantics></math></inline-formula>. Finally, these optimized filters are applied to delineate a filter bank for a cochlear implant design based on the Clarion processor model. |
| first_indexed | 2024-03-07T22:35:16Z |
| format | Article |
| id | doaj.art-29a65422358b4421a89f6cc638d2d7d1 |
| institution | Directory Open Access Journal |
| issn | 2411-9660 |
| language | English |
| last_indexed | 2024-03-07T22:35:16Z |
| publishDate | 2024-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Designs |
| spelling | doaj.art-29a65422358b4421a89f6cc638d2d7d12024-02-23T15:13:38ZengMDPI AGDesigns2411-96602024-02-01811610.3390/designs8010016Investigating the Performance of Gammatone Filters and Their Applicability to Design Cochlear Implant Processing SystemRumana Islam0Mohammed Tarique1Department of Electrical and Computer Engineering, University of Science and Technology of Fujairah, Fujairah P.O. Box 2202, United Arab EmiratesDepartment of Electrical and Computer Engineering, University of Science and Technology of Fujairah, Fujairah P.O. Box 2202, United Arab EmiratesCommercially 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 <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi>f</mi></mrow><mrow><mn>0</mn></mrow></msub></mrow></semantics></math></inline-formula> 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, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mo>|</mo><mi>H</mi><mo>(</mo><mi>f</mi><mo>)</mo><mo>|</mo></mrow></semantics></math></inline-formula>, 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,<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi>f</mi></mrow><mrow><mn>0</mn></mrow></msub></mrow></semantics></math></inline-formula>; temporal decay parameter, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>b</mi></mrow></semantics></math></inline-formula>; and order of the filter, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>n</mi></mrow></semantics></math></inline-formula>, can minimize the interference of the filter bank frequencies and very likely model the filter bandwidth (ERB), independent of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mfrac><mrow><msub><mrow><mi>f</mi></mrow><mrow><mn>0</mn></mrow></msub></mrow><mrow><mi>b</mi></mrow></mfrac></mrow></semantics></math></inline-formula>. Finally, these optimized filters are applied to delineate a filter bank for a cochlear implant design based on the Clarion processor model.https://www.mdpi.com/2411-9660/8/1/16basilar membraneclarion processorcochlear implantequivalent rectangular bandwidth (ERB)gammatone filter (GTF) bankpseudo-resonant frequency |
| spellingShingle | Rumana Islam Mohammed Tarique Investigating the Performance of Gammatone Filters and Their Applicability to Design Cochlear Implant Processing System Designs basilar membrane clarion processor cochlear implant equivalent rectangular bandwidth (ERB) gammatone filter (GTF) bank pseudo-resonant frequency |
| title | Investigating the Performance of Gammatone Filters and Their Applicability to Design Cochlear Implant Processing System |
| title_full | Investigating the Performance of Gammatone Filters and Their Applicability to Design Cochlear Implant Processing System |
| title_fullStr | Investigating the Performance of Gammatone Filters and Their Applicability to Design Cochlear Implant Processing System |
| title_full_unstemmed | Investigating the Performance of Gammatone Filters and Their Applicability to Design Cochlear Implant Processing System |
| title_short | Investigating the Performance of Gammatone Filters and Their Applicability to Design Cochlear Implant Processing System |
| title_sort | investigating the performance of gammatone filters and their applicability to design cochlear implant processing system |
| topic | basilar membrane clarion processor cochlear implant equivalent rectangular bandwidth (ERB) gammatone filter (GTF) bank pseudo-resonant frequency |
| url | https://www.mdpi.com/2411-9660/8/1/16 |
| work_keys_str_mv | AT rumanaislam investigatingtheperformanceofgammatonefiltersandtheirapplicabilitytodesigncochlearimplantprocessingsystem AT mohammedtarique investigatingtheperformanceofgammatonefiltersandtheirapplicabilitytodesigncochlearimplantprocessingsystem |