A dynamically reconfigurable mixed analog-digital filter bank

Abstract

A cochlea filter bank for an audible frequency range is used for an acoustic diagnosis, which detects defects of the outer wall. However, a straightforward implementation of a cochlea filter bank by conventional FIR filters uses a large number of taps. Thus, it requires a large amount of hardware. This paper proposes two methods to reduce the amount of hardware. The first one is to use a mixed analog-digital filter, which reduces the number of taps of the FIR filter. The second one is to apply a dynamic reconfiguration which reduces the number of filter banks. We implemented the filter bank by the PSoC1 and the Spartan 6 FPGA. Experimental results shows that the number of taps for the proposed one is reduced by 99.1% from a straightforward realization. Implementation of the acoustic diagnostic system shows the usefulness of the proposed one.