DSP-Implemented Broadband Superdirective Microphon e Array with Audible Noise Suppression

In this paper, a novel microphone linear array is proposed and implemented for real-time processing, working on a DSP processor in the frequency domain. The array, which is composed of 15 microphones in nested configuration, combines two multichannel techniques for speech improvement: SuperDirective beamforming (SD) and Audible Noise Suppression (ANS). The SD beamforming technique is an alternative to conventional or Delay and Sum beamforming (DS) with has worse low frequency spatial selectivity. ANS processing is based on the masking properties of the human auditory system and can benefit the perceived and objective quality of the processed signal. Although it has been successfully used in single channel systems, an enhanced multichannel version has been developed here, taking advantage of the extra information available in the acoustic spatial samples from the microphone array. Several on-line experiments are described here, assessing the real-time prototype.