Suppression of Instationary Distortions in Automotive Environments

Most speech enhancement systems contain some sort of background noise suppression as a basic building block and many different methods have been proposed therefore. However, many approaches yield reliable results only for stationary or slowly varying background noise and fail on highly instationary noise components. This contribution proposes a method for detecting instationary noise components when multiple microphones are available. The detection algorithm outputs an estimate of the instationary noise power spectral density itself and a short and long-term decision about the presence of instationary noise components. It is further shown, how these detectors can be used to enhance the performance of the subsequent signal enhancement algorithms such as noise suppression and microphone combination.