NOISE CANCELING SYSTEM

Under the condition where a plurality of background noise sources exists, there are arranged a first receiver, primarily receiving desired voice, and a plurality of second receivers each primarily receiving noise from a corresponding noise source. Filter coefficients of equivalent noise-producing filters, each having a frequency transmission characteristic equivalent to that of transmission path from its corresponding noise source to the first receiver, are estimated based upon mutual-correlation coefficients among the outputs of the first and second receivers and auto-correlation coefficients of the respective outputs of the second receivers. The noise signals from the equivalent noise-producing filters are subtracted from the output of the first receiver, thereby canceling the background noise. The filter coefficients estimation may be performed by using a maximum of the mutual-correlation coefficients between the outputs of the first receiver and the respective second receivers.