Design of efficient alterable bandwidth FIR filterbank for hearing aid system

Abstract

The lifestyle of any person depends on his ability to hear his surrounding sounds or voices. This is because each of our sense organs works interrelated. Without an ability to proper hearing, he/she cannot respond to the other person leading to a very less or no communication to the society. Although he has a good talent and knowledge within, he cannot be able to communicate or express unless he has a good hearing ability. Also, he faces emotive problems caused by a reduction in self-confidence. So, a requirement of designing an efficient hearing aid is much necessary to resolve the hearing loss problem. In this paper, design of an efficient alterable ten band Finite Impulse Response filter bank for the hearing aid is achieved. Among the various windowing techniques available, Hamming window is preferred to design the FIR filter owing to its relatively sharp main lobe width and also the first few lobes have good attenuation. In this filterbank, variability in the subband bandwidths is achieved by simply altering each subband's bandwidth and center frequency. Unlike fixed filterbank, the proposed design provides the advantage of matching most of the audiograms of different hearing-impaired persons more accurately with simple procedure leading to low cost and low hardware complexity. Also using an FIR filter in the filterbank leads to highly stable design. Thus, a design of highly qualitative filterbank compared to fixed bandwidth designs with high audiogram matching and less matching error is implemented.