Patent ID: 7473838

Claim:
A sound identification apparatus that identifies the sound type of an inputted audio signal, said apparatus comprising: a sound feature extraction unit operable to divide the inputted audio signal into a plurality of frames and extract a sound feature per frame; a frame likelihood calculation unit operable to calculate a frame likelihood of the sound feature in each frame, for each of a plurality of sound models; a confidence measure judgment unit operable to judge a confidence measure based on the sound feature or a value derived from the sound feature, the confidence measure being an indicator of whether or not to cumulate the frame likelihoods; a cumulative likelihood output unit time determination unit operable to determine a cumulative likelihood output unit time so that the cumulative likelihood output unit time is shorter in the case where the confidence measure is higher than a predetermined value and longer in the case where the confidence measure is lower than the predetermined value; a cumulative likelihood calculation unit operable to calculate a cumulative likelihood in which the frame likelihoods of the frames included in the cumulative likelihood output unit time are cumulated, for each of the plurality of sound models; a sound type candidate judgment unit operable to determine, for each cumulative likelihood output unit time, a sound type corresponding to the sound model that has a maximum cumulative likelihood; a sound type frequency calculation unit operable to calculate a frequency at which the sound type determined by said sound type candidate judgment unit appears in a predetermined identification time unit; and a sound type interval determination unit operable to determine the sound type of the inputted audio signal and the temporal interval of the sound type, based on the frequency of the sound type calculated by said sound type frequency calculation unit.