Constrained least square nonuniform dynamic filter bank for delay and Hardware efficient digital hearing aids

摘要

Hearing aid design requires a set of filters that provides reasonable audiogram matching for the specific type of hearing loss. Various fixed and reconfigurable filter banks are reported for different sound wave decomposition plans. But the delay and complexity of these structures are relatively large for a real hearing aid system. In this paper, a constrained least square, finite impulse response filter bank with low group delay and low hardware complexity is proposed. The method has considerable reduction in multiplications per sample and is more suitable for systems where the spectra of desired and undesired signals are overlapped. Coefficient decimation technique is used to vary the edge frequencies of the filters to make the system dynamic to accommodate the changes which can happen in future in. the audiogram pattern due to aging of user. The proposed delay and hardware efficient filter structure has synthesized using Xilinx software.