A Multichannel Noise Reduction Front-End Based on Psychoacoustics for Robust Speech Recognition in Highly Noisy Environments

Microphone array systems, due to their spatial filtering capability, usually overcome the traditional mono approaches in noise reduction. Moreover, the employment of psychoacoustically motivated speech enhancement schemes typically allows to achieve a good balance between noise reduction and speech distortion. This drove some of the authors to merge the two advantageous aspects into a unique solution, allowing to achieve relevant performances in terms of enhanced speech quality in a wide range of operating conditions. Now, in this paper, the objective is assessing the effectiveness of the approach when applied as Noise Reduction Front-end to an Automatic Speech Recognition system working in adverse acoustic environments. Some computer simulations have been carried out and they show that a significant improvement of recognition rate is registered when such front-end is used, also w.r.t. the performances achievable when another Multichannel Noise Reduction architecture, not based on psychoacoustics concepts, is adopted on purpose.