Patent ID: 7693712

Claim:
A pre-processing system of a signal of interest in an automatic speech recognition system in an interior space comprising: at least one non-acoustic sensor for sensing a non-acoustic noise signal existing in the interior space, a first conditioning unit connected to the non-acoustic sensor for conditioning a signal received by the non-acoustic sensor, a first filter bank connected to the first conditioning unit for dividing the received signal into a plurality of sub-bands of frequencies, at least one acoustic sensor for sensing the signal of interest emitting by a person which uses the automatic speech recognition, a second conditioning unit connected to the acoustic sensor for conditioning a signal received by the acoustic sensor, a second filter bank connected to the second conditioning unit for dividing the received signal into a plurality of sub-bands of frequencies, a pre-processing unit connected to the first filter bank and the second filter bank for pre-processing the received signal from the second filter bank for the automatic speech recognition system, wherein a pre-processing unit includes a section for processing signals with coherent frequency bands to suppress the noise from the signal provided by the second filter bank based on the received signals from the first and second filter bank, a section for processing signals with non-coherent frequency bands to suppress the noise from the received signal provided by the second filter bank based on the received signals from the first and second filter bank, a section of method selection for determining coherence properties of the received signal from the first and second filter banks, and for selecting one of the sections for processing signals with coherent frequency bands and the section for processing signals with non-coherent bands as a function of the result of the received signal properties, wherein the section for processing the non-coherent frequencies includes an estimation means for estimating a transfer function of the noise signal through the interior space and instantaneous noise estimation means for receiving the noise signal from the non-acoustic sensor and using the result provided by the estimation means and updating the estimated noise signal, the non-coherent frequencies suppressing the estimated noise signal from the received signals provided by the second filter bank.