Patent ID: 7822193

Claim:
A method of producing an estimate of the acoustic response of an environment, the method comprising: receiving a first signal, and a second signal, the second signal including an acoustic echo of the first signal; combining said first signal and said second signal to produce a third signal; combining said first signal with itself to produce a fourth signal; multiplying a first plurality of values sampled from said third signal by respective values generated using a first predetermined polynomial function and summing results of said multiplications to generate a first weighted mean of said third signal; multiplying a second plurality of values sampled from said third signal by respective values generated using a second predetermined polynomial and summing results of said multiplications to generate a second weighted mean of said third signal; computing a plurality of weighted means of said fourth signal; and generating said estimate from said first and second weighted means of said third signal and said plurality of weighted means of said fourth signal; wherein each of said first and second polynomial functions produces values for a predetermined set of discrete frequencies; and the method further comprises computing for each of said first and second polynomials a maximum frequency for which the output of the polynomial is non-zero and a minimum frequency for which the output of the polynomial is non-zero.