Noise detection device, noise detection method, and program

A noise detection method comprising:

• calculating, by an amplitude feature quantity calculator, an amplitude feature quantity in a waveform of a predetermined frame of an input signal of a voice;
• calculating, by a frequency feature quantity calculator, a frequency feature quantity in the waveform of the predetermined frame;
• calculating, by a feature variation calculator, based on one feature quantity among the amplitude feature quantities and the frequency feature quantities held in a holding unit that holds the amplitude feature quantities and the frequency feature quantities of a plurality of frames, a feature variation that is a variation in the feature quantity between two temporarily adjacent frames;
• comparing, by an interval specification unit, the feature variation with a previously set threshold value to specify an interval of temporarily continuous frames in which the amplitude feature quantities and the frequency feature quantities held in the holding unit are to be subjected to weighted averaging;
• generating, by a feature quantity set generation unit, as a feature quantity set, a set of respective weighted average values of the amplitude feature quantities and the frequency feature quantities corresponding to each of the frames of the specified interval;
• and
• determining, by a noise determination unit, whether a latest frame of the input signal is a frame including non-stationary noise that is sudden noise based on the feature quantity set.

A program causing a computer to function as a noise detection device comprising:

• an amplitude feature quantity calculator that calculates an amplitude feature quantity in a waveform of a predetermined frame of an input signal of a voice;
• a frequency feature quantity calculator that calculates a frequency feature quantity in the waveform of the predetermined frame;
• a feature variation calculator that calculates, based on one feature quantity among the amplitude feature quantities and the frequency feature quantities held in a holding unit that holds the amplitude feature quantities and the frequency feature quantities of a plurality of frames, a feature variation that is a variation in the feature quantity between two temporarily adjacent frames;
• an interval specification unit that compares the feature variation with a previously set threshold value to specify an interval of temporarily continuous frames in which the amplitude feature quantities and the frequency feature quantities held in the holding unit are to be subjected to weighted averaging;
• a feature quantity set generation unit that generates, as a feature quantity set, a set of respective weighted average values of the amplitude feature quantities and the frequency feature quantities corresponding to each of the frames of the specified interval;
• and
• a noise determination unit that determines whether a latest frame of the input signal is a frame including non-stationary noise that is sudden noise based on the feature quantity set.