Patent ID: 8694308

Claim:
A voice detection apparatus comprising: a provisional voice/ non-voice decision unit that provisionally decides an input signal to be voiced or non-voiced on a per frame basis; a voice/ non-voice decision unit that performs interval shaping on the voiced and non-voiced sequences of the provisional decision result, based on at least one of a voiced interval duration threshold value, which is a threshold value of a voiced interval duration used for deciding whether or not a frame of interest is in a voiced interval, and a non-voiced interval duration threshold value, which is a threshold value of a non-voiced interval duration used for deciding whether or not a frame of interest is in a non-voiced interval to find the voiced interval and the non-voiced interval of the input signal; and a threshold duration determination unit that determines at least one of the threshold value for the voiced interval duration and the threshold value for the non-voiced interval duration, on a per frame basis, based on at least one of a provisional threshold value of a voiced interval duration and a provisional threshold value of a non-voiced interval duration; at least one feature value of the input signal found for the frame of interest; and a threshold value for the feature value, wherein the duration threshold value determination unit determines the voiced interval duration threshold value, based on a value obtained by multiplying a ratio of the feature value of the input signal of a given frame to a threshold value of the feature value, raised to the power of a ratio of a weighting coefficient determined for the provisional voiced interval duration threshold value to a weighting coefficient determined for the feature value, by the provisional voiced interval duration threshold value, or a value obtained by multiplying a difference of the threshold value of the feature value of the input signal of the given frame and the feature value with a ratio of a weighting coefficient determined for the provisional voiced interval duration threshold value to a weighting coefficient determined for the feature value, and adding the provisional voiced interval duration threshold value to the multiplication value.