Kalman‐filters in subbands for noise reduction with enhanced pitch‐adaptive speech model estimation
Henning Puder · European Transactions on Telecommunications · 2002
Abstract In this paper, we present an approach for a Kalman filter which enhances single channel speech signals disturbed by car noise. For the Kalman filters, the speech and noise signals are modelled by AR processes and the corresponding models have to be estimated, based on the noisy speech. To avoid high model orders, the filtering is performed in subbands. We especially focus on the estimation of the speech model: First, standard model estimation methods are investigated and the method giving the best stable model is then utilized as a preliminary solution. To enhance the models without generating musical tones, a new method is proposed that utilizes estimates of the speaker's pitch frequency. The algorithm we present has less than 39 ms delay and thus fulfills the ETSI requirements for mobile telephony [1].