Theoretical Performance Analysis of ANC-Motivated Noise Reduction Algorithms for Open-Fitting Hearing Aids

Conference: IWAENC 2012 - International Workshop on Acoustic Signal Enhancement
09/04/2012 - 09/06/2012 at Aachen, Germany

Proceedings: IWAENC 2012

Pages: 4Language: englishTyp: PDF

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Dalga, Derya; Doclo, Simon (University of Oldenburg, Institute of Physics - Signal Processing Group, Oldenburg, Germany)

Existing noise reduction techniques for open-fitting hearing aids typically disregard the occurrence of signal leakage through the openfitting, leading to a degraded noise reduction performance. Recent miniaturization advances enable to incorporate an internal microphone in the ear mould, which is able to record this signal leakage. Recently, feedforward and combined feedforward-feedback active-noise-control-motivated algorithms for noise reduction have been proposed for open-fitting hearing aids. In this paper, a theoretical analysis of these algorithms is presented and the output signal-to-noise ratios (SNR) for a single speech source scenario are derived. It is shown that the performance of the combined feedforward-feedback ANC-motivated (FF-FB ANC) algorithm is independent of the signal leakage. In addition the FF-FB ANC algorithm delivers the highest output SNR of all considered noise reduction algorithms. Index Terms — active noise control, open-fitting hearing aid, noise reduction, Multichannel Wiener Filter