(19) United States
(12) Patent Application Publication (io) Pub. No.: US 2002/0097885 Al
Birchfield et al. (43) Pub. Date: Jul. 25,2002
(54) ACOUSTIC SOURCE LOCALIZATION SYSTEM AND METHOD
(76) Inventors: Stanley T. Birchfield, Santa Clara, CA (US); Daniel K. Gillmor, San
Francisco, CA (US)
(51) Int. CI.7 H04R 3/00; H04R 9/08;
(52) U.S. CI 381/92; 381/356; 381/122
FENWICK & WEST LLP
TWO PALO ALTO SQUARE
PALO ALTO, CA 94306 (US)
(21) Appl. No.: 09/922,370
(22) Filed: Aug. 2, 2001
Related U.S. Application Data
(60) Provisional application No. 60/247,138, filed on Nov. 10, 2000.
An acoustic source location technique compares the time response of signals from two or more pairs of microphones. For each pair of microphones, a plurality of sample elements are calculated that correspond to a ranking of possible time delay offsets for the two acoustic signals received by the pair of microphones, with each sample element having a delay time and a sample value. Each sample element is mapped to a sub-surface of potential acoustic source locations and assigned the sample value. A weighted value is calculated on each cell of a common boundary surface by combining the values of the plurality of sub-surfaces proximate the cell to form a weighted surface with the weighted value assigned to each cell interpreted as being indicative that a bearing vector to the acoustic source passes through the cell.