Investigations on design of efficient filter bank architectures for digital hearing aids

Abstract

The recent studies of WHO on hearing-related health issues show newlinethat Hearing Impairment related problems are increasing worldwide. One of newlinethe major solutions for Hearing Impairment is Digital Hearing Aids, but the newlineusage is only 17% across the world. Thus, design of efficient Digital Hearing newlineAid is an important research area. The hearing threshold of people may vary newlinefor different frequencies based on age, hearing impairment and other newlinephysiological factors. The critical component in a Digital Hearing Aid is newlineFilter Bank, which separates the individual frequency bands in the hearing newlinespectrum and provide independent amplification to individual bands based on newlinethe patient s audiogram to increase the listening comfort. The literature review show different approaches for implementing filter banks, namely uniform filter bank, non-uniform filter bank, and reconfigurable filter bank. The logarithmic nature of the human auditory newlinesystem favours non-uniform filter banks. On the other hand, reconfigurable newlinefilter banks are preferred when the hearing aid needs to be used for a wide newlinevariety of hearing impairments. The different techniques adopted for filter newlinebank design are Frequency Response Masking (FRM), Cosine Modulation, newlineVariable bandwidth filter, and hybrid techniques. Audiology research shows newlinethat a constraint-driven design approach is most suitable for designing and newlineimplementing filter banks in Digital Hearing Aids because they are batteryoperated, newlineconcealed, wearable devices with strict delay constraints. However, newlinerelaxing some of the constraints may increase other parameters, and a tradeoff newlinebetween these parameters need to be sought for implementing the filter newlinebanks. In this research, the design of efficient filter bank architectures for newlineDigital Hearing Aids based on various techniques are investigated. The main newlineobjectives of the research are: (i) To design fixed non-uniform filter banks for Sensorineural Hearing Loss (SNHL) using Frequency Response Masking (FRM) and newlineCosine Modulated (CMFB) techniques (ii) To design Reconf