Beamforming microphone arrays for speech acquisition in noisy environments

In this paper we present an adaptive microphone array with adaptive constraint values to suppress coherent as well as incoherent noise in disturbed speech signals. We use a generalized sidelobe cancelling (GSC) structure implemented in the frequency domain since it allows a separate handling of determining the adaptive look-direction response to suppress incoherent noise and adjusting the adaptive filters for cancellation of coherent noise, The transfer function in the look-direction is an adaptive Wiener-Filter which is estimated by using the short-time Fourier transform and the Nuttall/Carter method for spectrum estimation. The experimental results demonstrate that the proposed method works well for a large range of reverberation times and is therefore able to operate independently of the correlation properties of the noise field.