Low Complexity Implementation of Efficient Reconfigurable Structure for Cost-Effective Hearing Aids using Fractional Interpolation

Abstract

Digital hearing aids can be made less expensive if they are reconfigurable and of low hard- ware complexity. Hence, this work proposes a hardware-efficient, reconfigurable filter bank structure, based on fractional interpolation. The proposed structure is reconfigurable since a single structure can be used for different patients with different types of hearing im- pairments. The proposed structure consists of a masking stage and a scheme generation stage with a prototype filter in each stage. The prototype filters are made multiplier-less by representing their coefficients in the CSD space. The filter characteristics are improved by deploying a MOABC optimization algorithm. The number of adders is reduced using the SIDC-CSE technique. The low-complexity structure can be used for all types of hearing im- pairments, with the matching error and delay within tolerable ranges. The proposed struc- ture has been implemented on an FPGA to support the analytical results for low hardware complexity and hence low power.