Speech quality and stable gain trade-offs in adaptive feedback cancellation for hearing aids

Abstract

This paper addresses trade-offs in adaptive feedback cancellation (AFC) for hearing aids. Aggressive AFC for improved added stable gain (ASG) reduces speech quality. In this paper, the hearing-aid speech quality index (HASQI) is used to investigate AFC performance before the system becomes unstable. It is demonstrated that for a desired speech quality, multiple AFC algorithms can be evaluated for their ASG and computational efficiency. An example is presented with HASQI = 0.8, baseline AFC, and two advanced approaches. For the advanced AFCs, ASG gains of 4 and 7 dB were obtained at additional computational complexity of 8% and 11%, respectively.

Figures

Fig. 1.

Block diagram of the AFC framework.

Fig. 2.

The (a) impulse response and (b) frequency response of the feedback path used in the simulation.

Fig. 3.

(Color online) The resulting HASQI curves of the AFC algorithms.