Auditory filterbank design using tunable passive digital filters

Abstract

We introduce a class of first-order high-pass and second-order low-pass tunable passive digital filters for auditory filterbank design. The high-pass passive digital filter is used to approximate the frequency response of the outer and middle ear. The low-pass passive digital filters offer a suitable filter-class for parametric tuning control over the bandwidth and the center frequency of each parallel filter in the filter bank. The asymmetry frequency response property of these low-pass digital filters makes them a suitable candidate for approximating the psychoacoustic characteristic of the human ear. Due to their pseudopassivity property, these tunable passive digital filters are oscillation-free under finite word length operations. Design of an auditory filter band consisting of one first-order high-pass in cascade with multiple parallel second-order low-pass tunable passive digital filters is given.