A Computationally Efficient 11 Band Non-Uniform Filter Bank for Hearing Aids Targeting Moderately Sloping Sensorineural Hearing Loss

Sajan P Philip ,Sampath Palaniswami ,Harikirubha Sivakumar

doi:10.33180/infmidem2020.301

Abstract

A computationally efficient 11 band non-uniform filter bank addressing low or moderately sloping sensorineural hearing loss - the most common type of hearing problem- is proposed. This structure is suitable for low cost, small area implementations of hearing aids. The computational efficiency is achieved by adopting the Frequency Response Masking technique, which uses only two prototype filters with a total of 19 multipliers at 80dB stopband attenuation for the design of entire non-uniform filter bank. The computational complexity analysis shows that the proposed method provides about a 70-90% reduction in computational resources compared to non-FRM methods and about a 40-80% reduction in computational resources compared to the other FRM methods. The audiogram matching performance analysis shows that the matching error of the proposed filter bank is negligible even without optimization. The delay performance of the filter bank is acceptable for both Closed Canal Fittings and Open Canal Fittings.

Highlights

The pioneering work by eminent researchers in multirate Digital Signal Processing (DSP), as summarized in [1,2], had a tremendous impact on different fields of digital signal processing applications like Hearing Aids (HA)
To make the structure ideal for Open Hearing Aid Fitting (OHAF), we have proposed the second structure, which reduces the delay by removing a higher-order interpolation filter branch at the low-frequency region of the basic 12 band NUFB
Out of the eight different audiograms available, four are considered for evaluation. These four audiograms are selected based on the criteria of the proposed design, that is, the proposed filter bank design is for mild or moderate sloping Audiograms

Summary

Introduction

The pioneering work by eminent researchers in multirate Digital Signal Processing (DSP), as summarized in [1,2], had a tremendous impact on different fields of digital signal processing applications like Hearing Aids (HA). Digital HA, as an assistive listening device, has numerous advantages over its analog counterpart. Flexibility in frequency-dependent speech amplification, programmability, reconfigurability, noise suppression, feedback cancellation, and stability of the system against ageing are some of the critical advantages of digital HA. The significant concerns of HA design are group delay, power consumption, size of the device, and design complexity. S. P Philip et al.; Informacije Midem, Vol 50, No 2(2020), 153 – 167

Methods

Results

Conclusion