The application of maximal flat delay filter in cochlear implants
Yousheng Chen, Yurui Zhong, Weifang Chen, Xu Yuan · 2024
In cochlear implants, delay sum beamforming and adaptive beamforming techniques play a pivotal role in noise reduction. A crucial aspect of these multi-microphone algorithms lies in the delay value, which dictates the directional patterns of beamformers. Limited by the compact design of cochlear implants, the physical spacing between microphones is often restricted, necessitating the use of fractional sampling delay. This article delves into the utilization of maximum flat fractional delay filters in cochlear implants. It meticulously analyzes the characteristics of these filters across varying orders, discussing factors such as design processes, coefficient analysis, filter order comparisons, system amplitude frequency responses, group delay behaviors, and zero pole configurations. The findings of this article offer profound insights for the enhanced engineering application of multi-microphone noise reduction algorithms in cochlear implants.