Patent ID: 8036888
Filing Date: 2011-10-11
Classification: H04R

Abstract:
1. A collecting sound device with directionality comprising: a plurality of voice accepting means for accepting a sound input from sound sources existing in a plurality of directions and converting the sound input into a signal on a time axis; signal converting means for converting each signal on a time axis into a signal on a frequency axis; phase component computing means for computing a phase component of each signal on a frequency axis converted by the signal converting means for each frequency; phase difference computing means for computing a difference of phase components between signals on a frequency axis computed by the phase component computing means; probability value specifying means for specifying a probability value indicative of probability of existence of a sound source in a predetermined direction based on the difference of phase components computed by the phase difference computing means; suppressing function computing means for computing a suppressing function to suppress a sound input from a sound source other than a sound source in a predetermined direction based on the probability value specified by the probability value specifying means, whereby the suppressing function is a function of the difference of phase components computed by the phase difference computing means; signal correcting means for multiplying an amplitude component of a signal on a frequency axis by the computed suppressing function and correcting the converted signal on a frequency axis; signal restoring means for restoring the corrected signal on a frequency axis to a signal on a time axis; and means for computing a separation phase width corresponding to a range of the phase component, for which a sound input from a sound source other than a sound source in a predetermined direction needs to be suppressed, based on the probability value specified by the probability value specifying means; wherein a width of the phase difference in which a sound source exists in a predetermined direction is set for each frequency based on the computed difference of phase components by the phase difference computing means, and the suppressing function is set to 1 within the range of the set width of the phase difference; and wherein the suppressing function is set to 1 in the phase width and set as a positive real number which gradually decreases with distance from the phase width and becomes 0 in a range beyond the computed separation phase width.