Patent ID: 8369550

Claim:
A method for detecting the direction of a sound source, comprising: inputting sound signals from a sound source to a plurality of microphones wherein a structure is located between the plurality of microphones; measuring respective output signals from the plurality of microphones in response to the input sound signals; determining whether the sound source is in front of or behind the structure, based on the difference between amplitudes of the respective output signals caused by the structure; and determining an angle corresponding to the position of the sound source from a difference between delay times of the respective output signals, wherein in the determining whether the sound source is in front of or behind the structure, when G FB (ƒ k ) denotes a cross power density function between the respective output signals of first and second microphones of said plurality of microphones and G BB (ƒ k ) denotes a power spectral density function of the output signal of the second microphone, an inter-channel transfer function (IcTF) between positions of the microphones is defined as follows: IcTF FB ⁡ ( f k ) = G FB ⁡ ( f k ) G BB ⁡ ( f k ) =  IcTF ⁡ ( f k )  ⁢ ⅇ j · phase ⁡ ( f k ) and an inter-channel level difference (IcLD) is defined as follows: IcLD = 20 ⁢ ⁢ log 10 ⁡ (  IcTF ⁡ ( f )  ) = ∑ n = 0 n = N - 1 ⁢ 20 ⁢ ⁢ log 10 ⁡ (  IcTF FB ⁡ ( f n )  ) ⁢ df n ∑ n = 0 n = N - 1 ⁢ df n ⁢ ⁢ dB wherein, in the determining whether the sound source is in front of or behind the structure, the position of the sound source is determined as a front with respect to a line passing through the first and second microphones when the IcLD is greater than zero, and the position of the sound source is determined as a back with respect to the line passing through the first and second microphones when the IcLD is smaller than zero.