Techniques to enhance voice signals in a dual
microphone system are disclosed. According to one aspect of the present invention, there are at least two microphones that are positioned in a pre-configured array. Two audio signals x1(k) and x2(k) are received and coupled to an adjusting module that is provided to control the
gain of each of the audio signals x1(k) and x2(k) to minimize
signal differences between the two signals. A separation module is provided to receive matched audio signals x′1(k) and x′2(k) from the adjusting module. The separation module separates the audio signals x′1(k) and x′2(k) to obtain a first
audio signal s(k) containing mainly the voice and a second
audio signal n(k) containing mainly the
noise. An adaptive filtering module is provided to eliminate the
noise component in the
audio signal s(k) to obtain an estimated voice
signal e_s(k) with a higher S / N ratio. Furthermore, the adaptive filtering module can be also configured to suppress echo in the audio
signal s(k) at same time. The voice signal e_s(k) may be further coupled to a single-channel voice enhancement module that is configured to eliminate any residual of the
noise component in the voice signal e_s(k) according to the differences between the voice signal and the noise signal in
time domain and
frequency domain, whereby, the S / N ratio is further enhanced.