| 摘要 |
<P>PROBLEM TO BE SOLVED: To accurately calculate arrival time from a speaker to a listening position without making a user feel unpleasant due to jarring measurement sound. <P>SOLUTION: A cycle of a sinusoidal wave signal S1 which is output as measurement sound from a sub-woofer SW is set to one cycle to two cycles. When the measurement sound based on the sinusoidal wave signal S1 is output from the sub-woofer SW, it is collected by a microphone MF at an arbitrary listening position, and filtering processing is applied in a time-axis direction and in a bacward time-axis direction in order to remove a high frequency component HF of a measurement sound waveform WV1 obtained at that time. A rising edge UE1 of the first wave WF1B in a measurement sound waveform WV1B after filtering, which is obtained as a result, is detected as a receiving timing t<SB>1</SB>of the measurement sound by using a threshold TH1. <P>COPYRIGHT: (C)2008,JPO&INPIT |
