Patent ID: 7039198

Claim:
A method of forming information for determining a direction of an acoustic source using at least three spaced-apart microphones, the microphones coupling acoustic signals from at least two pairs of microphones with each pair of microphones receiving two acoustic signals and having a separation distance and an orientation of its two microphones, the method comprising: for each pair of microphones, calculating a plurality of sample elements for the two acoustic signals received by the pair of microphones, the plurality of sample elements corresponding to a ranking of possible time delays between the two acoustic signals received by the pair of microphones with each sample element having a time delay and a numeric sample value; for the plurality of sample elements of each pair of microphones, mapping each sample element to a sub-surface of potential acoustic source locations according to its time delay and the orientation and the separation distance of the pair of microphones for which the sample element was calculated, and assigning the sub-surface the sample value of the sample element, producing a plurality of sub-surfaces for each pair of microphones; for a boundary surface intersecting each of the plurality of sub-surfaces, the boundary surface divisible into a plurality of cells, calculating a weighted value in each cell of the boundary surface by combining the sample values of the plurality of sub-surfaces proximal the cell to form a weighted surface with the weighted value of each cell of the weighted surface being indicative of the likelihood that the acoustic source lies in a direction of a bearing vector passing through the cell.