Patent ID: 8111831

Claim:
An acoustic apparatus, comprising: positive value conversion means for converting a response signal into a succession of positive-valued peaks, the response signal being obtained by collecting a test signal using a microphone, the test signal being emitted from a speaker; detection means for detecting a first transient response part by (a) selecting a first one of the succession of positive-valued peaks of the converted response signal as a first transient response part candidate, (b) determining whether the first transient response part candidate conforms to one or more discarding conditions, and (c) establishing the first transient response part candidate as the first transient response part in response to determining that the first transient response part candidate does not conform to the one or more discarding conditions, and in response to determining that the first transient response part candidate conforms to the one or more discarding conditions, selecting a portion of another converted response signal as the first transient response part candidate and repeating (b) and (c); estimation means for estimating a rise point of the converted response signal from at least N sampling points, wherein N is a positive integer, that contain a peak position of the first transient response part or the vicinity thereof; and computation means for computing a time delay of audio collected by the microphone based on the estimated rise point and on a timing at which the test signal is generated.