Stereophonic Acoustic Echo Suppression for Speech Interfaces for Intelligent TV Applications

In this paper, a unified framework for using speech interfaces with intelligent televisions (TVs) is proposed. The proposed framework is primarily based on suppressing the stereophonic acoustic echo of the TV audio sounds and adaptive tracking of the time varying acoustic transfer function (ATF) of the echo sounds. In order to effectively suppress the acoustic echoes from the TV speakers, an optimal filter with a multichannel subspace approach is imposed on noisy inputs and the second order statistics of the stereophonic echoes are adaptively estimated by tracking the time varying ATF using the normalized least mean square method. Through assessing the proposed method with a database collected in real TV watching environments, noticeable improvements were achieved in the signal to noise ratio gain, Itakura–Saito distance, and speech recognition rates.