Novel Binaural Spectro-temporal Algorithm for Speech Enhancement in Low SNR Environments

A novel BInaural Spectro-Temporal (BIST) algorithm is proposed in this paper to increase the speech intelligibility in low or negative SNR noisy environments. The BIST algorithm consists of two modules. One is the spatial mask for receiving sound from the specific direction, and the other is the spectro-temporal modulation filter for noise reduction. Most speech enhancement algorithms are not applicable in harsh environments because the energy of speech is covered by the noise. To increase the speech intelligibility in low or negative SNR noisy environments, a distinctive approach is proposed to solve this problem. First, the BIST algorithm takes binaural auditory processing as a spatial mask to separate the speech and noise according to their locations. Next, the modulation filter is applied to reduce the noise source in the scale-rate (spectro-temporal modulation) domain according to their different acoustic feature. It works like the spectro-temporal receptive field (STRF) which is the perception response of human auditory cortex. The experimental results demonstrate that the proposed BIST speech enhancement algorithm can improve 20% from the noisy speech at SNR-10dB.