| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method and a device in which even in a field of high reflection sound, a sound source direction of direct sound can be estimated easily and accurately and even impulse sound can also be extracted accurately. <P>SOLUTION: When estimating a sound source direction by calculating a sound arrival time difference D<SB POS="POST">13</SB>between microphones M1 and M3 and a sound arrival time difference D<SB POS="POST">24</SB>between microphones M2 and M4 from a sound pressure signal sampled by using the first and second microphone couples (M1, M3) and (M2 and M4) disposed on two straight lines crossing each other, fast Fourier transform for an extremely short time in which the length of an analysis interval is 0.1 to 10 msec. is performed N times, cross spectrums p<SB POS="POST">n13</SB>, p<SB POS="POST">n24</SB>and amplitude values w<SB POS="POST">n13</SB>, w<SB POS="POST">n24</SB>between M1 and M3 and between M2 and M4 are calculated, and arrival time differences D<SB POS="POST">13</SB>, D<SB POS="POST">24</SB>are calculated from weighted average cross spectrums P<SB POS="POST">13</SB>, P<SB POS="POST">24</SB>obtained by performing weighted averaging on these cross spectrums p<SB POS="POST">n13</SB>, p<SB POS="POST">n24</SB>with the amplitude values w<SB POS="POST">n13</SB>, w<SB POS="POST">n24</SB>. <P>COPYRIGHT: (C)2013,JPO&INPIT |
