Patent ID: 7769184

Claim:
A sound field measurement apparatus comprising: a signal generating unit for outputting a burst signal; a driving unit for driving a speaker using the burst signal; a microphone for picking up an audio output from the speaker; an analog-digital converter for performing analog-digital conversion processing on an output signal from the microphone and outputting picked-up audio data; a filtering unit for performing filtering processing on the picked-up audio data; and an analyzing unit for determining a propagation time of the audio output from the speaker to the microphone in accordance with data output from the filtering unit, wherein the filtering unit is an IIR filter configured to filter the picked-up audio data forward along a time axis and then filter the picked-up audio data backward along the time axis, or an IIR filter configured to filter the picked-up audio data backward along the time axis and then filter the picked-up audio data forward along the time axis.