Study and Analysis of Audiogram Matching for Reconfigurable FIR Filter Bank Use in Hearing Aids

摘要

Hearing loss is becoming a common problem due to continuous use of headphones for long period and people who work in noisy industrial environments. We found many young and old people use a hearing aid device for their hearing loss problems. Digital hearing-aid device is electronics device which is now comes in very compact size which fits in ear cavity. Digital hearing aids selectively filters sound signals and add gain to sound signals and compensate hearing loss of patients ear .ENT doctors perform hearing test of patient having hearing loss problem and plot hearing loss of each ear as a function of frequency and loss this plot is called as Audiogram. Audiologist program hearing aid as per audiogram prescription formula for gain. Digital filters in hearing aid device filter and amplify the processed signal and transfer it to the ear. Continuous research on design of digital filters is going on o use in hearing aid device improvement. Present hearing aid devices are more adaptive to individual patient hearing loss characteristics. These filter designs use filter banks with fixed sub-bands. Current research focus is on to reduce the algorithm complexity. In this paper, we are focusing our study of Audiogram matching for different types of hearing loss use by using single reconfigurable transfer function type of digital FIR filter. This reconfigurable filter fitting to audiogram mentioned in IEC 60118-15 standard will be checked. Matching results found very satisfactory compared with the fixed filter banks. In next sections, details regarding reconfigurable transfer function FIR filter bank and audiogram matching mentioned.