| 摘要 |
<P>PROBLEM TO BE SOLVED: To accurately calculate arrival time from a speaker to a listening position with a simple configuration. <P>SOLUTION: A sinusoidal wave signal S1 which is output as a measurement sound from a sub-woofer SW is generated, and the measurement sound is output from the sub-woofer SW. In order to remove a high frequency component HF of a measurement sound waveform WV1 obtained when the sound is collected by a microphone MF, filtering processing in a time-axis direction and in a time-axis backward direction is applied. A threshold TH1 for detecting a rising edge UE1 of a first wave WF1B in a measurement sound waveform WV1B after filtering processing which is obtained as a result, is set by using a multiplication result of a predetermined percentage to a maximum peak value PK1 of the measurement sound waveform after the filtering process. The rising edge UE1 of the first wave WF1B in the measurement sound waveform WV1B after filtering is detected as a receiving timing t<SB>1</SB>of the measurement sound by using the threshold TH1. <P>COPYRIGHT: (C)2008,JPO&INPIT |
