Patent ID: 8620650

Claim:
An apparatus for combining signals comprising: a first microphone generating a first input signal having a first voice component and a first noise component; a second microphone generating a second input signal having a second voice component and a second noise component; a mixing circuit configured to: apply a first gain having a value Î± to the first input signal to produce a first scaled signal; apply a second gain having a value 1âˆ’Î± to the second input signal to produce a second scaled signal; and sum the first scaled signal and the second scaled signal to produce a summed signal; and an adaptive filter configured to compute an updated value of Î± to minimize the energy of the summed signal based on the summed signal, the first input signal and the second input signal, and to provide the updated value of Î± to the mixing circuit, wherein the adaptive filter is configured to apply a least-mean-squared algorithm to compute the updated value of Î±, and the adaptive filter is implemented in a digital signal processor programmed to compute a difference between the first and second signals, multiply the summed signal by the difference and by a pre-determined step size value, and subtract the product from the current value of Î± to produce the updated value of Î±.