Abstract: A computer-implemented method for measuring the directions of arrival, DOAs, of acoustic signals recorded by a microphone array outputting audio signals, comprising: bandpass-filtering the audio signals into at least one spectral band; in each spectral band, for at least one pair of microphones, computing a cross-product between the audio signals of said pair, iteratively minimizing an error between the cross-products and model cross-products calculated from DOA estimates, and determining those DOA estimates whose powers constitute local maxima, as DOA candidates; and measuring the DOAs of the acoustic signals from the DOA candidates of all spectral bands. Further disclosed is an apparatus for performing this method.

Abstract: The invention relates to a computer-implemented method for updating at least one frequency-domain filter coefficient Wi,j(k) of an echo canceller having at least one channel and at least one segment per channel, the filter coefficients of the echo canceller being updateable in the frequency domain at a time block m comprising: determining a canceller output Em(k) over the nth time block; determining a canceller error ?(k) over the m?th time block; determining a look-backward error (k); determining a look-forward error {right arrow over (?)}(k) as {right arrow over (?)}k)=Em(k)??{right arrow over (?)}(k) wherein {right arrow over (?)}(k) is based on ? i = 0 C - 1 ? ? j = 0 S - 1 ? ? ? ( k ) ? X i , j , m - ? ? * ? ( k ) ? a = 0 C - 1 ? ? b = 0 S - 1 ? ? X a , b , m - ? ? ( k ) ? 2 + ? ? X i , j , m ? ( k ) ; determining an optimal update step-size ?i,j,m(k) from said canceller output Em(k) over the nth ti