Variable-bandwidth filter-bank for low-power hearing aids

This paper proposes a variable filter-bank (VFB) for low-power digital hearing aids. This VFB is designed using digital spectral transformation. After proving transformations from a digital prototype lowpass filter into variable lowpass filter (LPF), variable bandpass filter (BPF), and variable highpass filter (HPF), we demonstrate how to optimize the parameters of the VFB for optimally fitting a given audiogram. An example will be given to show that a low-order (second-order) VFB can achieve very accurate audiogram fitting. Such a VFB requires much fewer multipliers than the conventional fixed-bandwidth filter-bank, and thus reduces power consumption significantly.