Separation of Multiple Signals in Hearing Aids by Output Decorrelation and Time-delay Estimation

Sensori-neural hearing impaired listeners have difficulty in separating multiple signals or perceiving speech in background noise and hearing aids are widely used to enhance the desired signal. In this paper we present a simple two-input system to separate two signals using output decorrelation where the filter coefficients are adaptively estimated to minimise the correlation of the output signals. In particular we show that an optimal filter can be designed and the convergence behaviour can be greatly improved by using a time-delay estimation technique. The algorithm was implemented to successfully separate two signals and the results are presented.