The IUP Journal of Telecommunications
Reconfigurable Filter Design and Testing with ISTS Standard for Proposed Hearing Aid Application

Article Details
Pub. Date : August, 2020
Product Name : The IUP Journal of Telecommunications
Product Type : Article
Product Code : IJTC40820
Author Name : Manik S Sonawane and S R Chougule
Availability : YES
Subject/Domain : Arts & Humanities
Download Format : PDF Format
No. of Pages : 18

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Abstract

Digital Hearing Aid (DHA) device selectively filters sound signals in subbands.Gain is added as per hearing loss mentioned in audiogram. DHA uses digital filters and amplifies processed signal, and this signal is transferred to the ear. Multiple DHA manufacturing companies all over world have innovative and miniature DHA devices in their product range. They do rigorous research and development to improve product functionalities. Most of them use design method of digital filters using selective amplification by adding gain to subband where patients have hearing loss. Nowadays, DHAs are more customized to individual patient hearing loss characteristics. Most of the available hearing aid designs use filter banks with fixed subbands. The paper focuses on reducing the complexity of the algorithms improving DHA user experience in changing noise and proposes a single reconfigurable transfer function type of digital Finite Impulse Response (FIR) filter to achieve a best fitting to audiogram as per the specifications with IEC 60118-15 standard, and the processed signals are tested with ITU-TPESQ standards. The paper uses International Speech Test Signal (ISTS) standard speech audio signal to test designed filter, and the results are found to be very satisfactory compared with the fixed filter banks. The paper discusses combined or reconfigured transfer function approach for use in DHA devices and design of reconfigurable FIR filter bank with adjusting different parameters in terms of requirements of DHA.


Introduction

Digital Hearing Aid (DHA) is very beneficial for people having hearing loss problems. These patients can get hearing benefit using a DHA device. In real world, only 20% of hearing affected patients purchase a hearing aid and around 25% of them do not use DHA due to irritating noise and unpleasant whistles. Some DHAs have processed signal with other amplified noises due to surrounding background noise


Keywords:

Hearing loss, Digital Hearing Aid (DHA), Digital filters, Reconfigurable filter, Perceptual Evaluation of Speech Quality (PESQ), International Speech Test Signal (ISTS)