Microphone array speech enhancement in overdetermined signal scenarios

The problem of enhancing noisy speech by using a microphone array is considered. An algorithm called the graphic equalizer (GEQ) array is presented which trades off signal degradation for additional interference suppression. The algorithm is based on the concept of directly modifying the short-time spectral magnitude of the sum of the received signals. Simulation results are given that illustrate the advantages of using the GEQ array for diffuse-noise scenarios and for scenarios involving more interference signals than array degrees of freedom. The GEQ array was shown to outperform the Frost array for diffuse-noise and overdetermined signal scenarios, in which the Frost array was not capable of attenuating all of the interference with one broad null. While the GEQ array did not always yield a better SNR than the Frost array for these scenarios, it often outperformed the Frost array in terms of the power function spectral distance measure, a measure that is more highly correlated with human auditory perception than is the SNR.<>