Patent ID: 8068627

Claim:
An apparatus, comprising: an omnidirectional microphone having a first reception profile; a directional microphone having a second reception profile; an omni input adapted to receive digital samples representative of signals received by the omnidirectional microphone; a directional input adapted to receive digital samples representative of signals received by the directional microphone; a mixing module connected to the omni input, the mixing module providing a mixing ratio for a block of digital samples, α(k); a compensation filter connected to the directional input and the mixing module, the compensation filter adapted to output a third reception profile which substantially matches the first reception profile; a first multiplier receiving the omni input and a signal value of (1−α(k)) from the mixing module; a second multiplier receiving the directional input and a signal value of α(k) from the mixing module; and a summing stage adding outputs of the first multiplier and the second multiplier, wherein the output signal for sample n of block k, s c (n,k), is provided by: s c ( n,k )=(1−α( k ))* s O ( n,k )+α( k ) s D ( n,k ), where s O (n,k) is the output of the omni microphone for sample n of block k and s D (n,k) is the output of the compensation filter for sample n of block k, and α(k)=C*α(k−1)+(1−C)*β(k), and where C is a constant between 0 and 1 and β(k) is an output from the compensation filter for block k.