Algorithm Research and Hardware Realization of Band-limited NLMS for Hearing Aid

A new band-limited Normalized Least-Mean-Square adaptive feedback suppression algorithm based on high-pass pre-fihering for hearing aid applications has been developed. Compared with the traditional wideband NLMS algorithm, the proposed algorithm provides higher efficiency by filtering out the unwanted frequency bands where the oscillation frequencies are not located. There are significant improvements of WEVN reduction, convergence stability and SFR through simulations. The details of hardware design of the algorithm have also been analyzed. The post-simulation power dissipation is only 127μm with a system clock frequency of 1MHz.