A real-time auditory-based microphone array assessed with E-RASTI evaluation proposal

In this paper, a real time nested microphone array based on the auditory properties of the human ear is presented. Three different stages in the development of the system are described. Firstly, the design of the new auditory-based microphone array is presented, obtaining better noise reduction using the masking properties of the human auditory system. Secondly, we show its validation through a new method called E-RASTI based in the well-known RASTI (Rapid STI - speech transmission index) intelligibility estimator. In addition to classical enhancement estimators as SNR, NMR (noise to masked ratio) or AI (articulation index), E-RASTI is proposed and validated for dereverberation assessment, used here with real speech signals and not with speech-like signals as in the original RASTI method. And finally as third stage, the real time implementation of this highly computing-demanding algorithm through the use of a DSP-based architecture based on the recent floating point TMS320C6701 is described.