A novel low-voltage low-power wave digital filter bank for an intelligent noise reduction digital hearing instrument

We propose an acoustic noise suppression system embodying a novel low-voltage low-power multiplexed 16-channel lattice wave digital filter bank (LWDFB) for an intelligent digital hearing instrument. This system alleviates the intensity of the computation problem and eliminates the delay problem of FFT-IFFT-based systems. To satisfy the tight constraints of low voltage, low power and a small IC area realization for a practical digital hearing instrument, and yet realize an equivalent of a 160-pole filter function, we propose a LWDFB which employs a multiplexed bit-parallel approach, clock gating and other low power methodologies. The LWDFB draws approximately 480 μA at 1.1 V supply voltage, and occupies an area of 3.8 mm² in a 0.35 μm CMOS process