Noise reduction by paired-microphones using spectral subtraction

This paper proposes a method of noise reduction by pairedmicrophones as a front-end processor for speech recognition systems. This method estimates noises using a subtractive microphone array and subtracts them from the noisy speech signal using the Spectral Subtraction (SS). Since this method can estimate noises analytically and frame by frame, it is easy to estimate noises not depending on these acoustic properties. Therefore, this method can also reduce non stationary noises, for example sudden noises when a door has just closed, which can not be reduced by other SS methods. The results of computer simulations and experiments in a real environment show that this method can reduce LPC log spectral envelope distortions.