| 摘要 |
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 x<SUB>1</SUB>(k) and x<SUB>2</SUB>(k) are received and coupled to an adjusting module that is provided to control the gain of each of the audio signals x<SUB>1</SUB>(k) and x<SUB>2</SUB>(k) to minimize signal differences between the two signals. A separation module is provided to receive matched audio signals x'<SUB>1</SUB>(k) and x'<SUB>2</SUB>(k) from the adjusting module. The separation module separates the audio signals x'<SUB>1</SUB>(k) and x'<SUB>2</SUB>(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.
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