Digital Hearing Aids Using Automated Varying Bandwidth Finite Impulse Response Filter Banks

Abstract

A human auditory system is a highly complex sensitive system which transfers the acoustic sound into neuroelectrical signals toward the brain. Hearing difficulties or deafness are the outcomes of the problems occurred at any part of the auditory system. Assistive technologies such as hearing aids are developed to improve the quality of life of the hearing impaired people. Current digital hearing aids have fixed bandwidth filter banks which cannot provide enough flexibility to match with audiogram of different hearing loss. Recently, variable bandwidth filter banks have been introduced with different technologies to match more closely with the audiogram of a particular hearing loss. This research work proposes and implements a software controlled variable bandwidth FIR filter bank using Matlab GUI. In the Matlab GUI, in the filter bank, the bandwidth of every filter is adjusted dynamically in the Matlab GUI such that it fits more closely to the audiogram of a particular hearing loss. An experiment has been conducted in the developed Matlab GUI with various hearing loss, and the results show that the proposed system matches the filter bank magnitude response very closely to the audiogram of a particular hearing loss and reduces the matching error.