GENERATION METHOD OF AUDIO SIGNAL, AUDIO SYNTHESIZING DEVICE
An audio signal method of the present disclosure includes: inputting a plurality of variables including at least a first variable indicating an opening degree of a throat, which interiorly includes a vocal cord, with respect to a vocal cord model configured to output a second variable indicating an opening degree of the vocal cord according to reception of input of the plurality of variables, the first variable being greater than the second variable; and generating an audio signal in which a level of a non-integer harmonic sound is changed, by controlling the second variable.
1 . A method of generating an audio signal, the method comprising:
inputting a plurality of variables including at least a first variable indicating an opening degree of a throat, which interiorly includes a vocal cord, with respect to a vocal cord model configured to output a second variable indicating an opening degree of the vocal cord according to reception of input of the plurality of variables, the first variable being greater than the second variable; and
generating an audio signal in which a level of a non-integer order harmonic sound is changed, by controlling the second variable.
2 . The method of generating an audio signal according to claim 1 , wherein the plurality of variables includes a variable set in advance for each phoneme.
3 . The method of generating an audio signal according to claim 1 , wherein timing for controlling the second variable is differed according to a type of phoneme.
4 . The method of generating an audio signal according to claim 1 , further comprising:
receiving an instruction for setting to either a natural voice mode or high voice mode; and
generating an audio signal in which levels of a first formant frequency, a second formant frequency, and a high-order integer harmonic sound are attenuated when receiving the instruction for setting to the high voice mode compared to when receiving the instruction for setting to the natural voice mode, an attenuation rate of the levels of the first formant frequency and the second formant frequency being lower than an attenuation rate of the level of the high-order integer order harmonic sound.
5 . The method of generating an audio signal according to claim 1 , wherein
the vocal cord model simulates an inclusion of,
a first mass point coupled to a first fixed end via a first spring,
a second mass coupled to a second fixed end, disposed at a position facing the first fixed end, in a direction opposing the first mass point by way of a second spring,
a third mass point coupled to a surface opposite to a surface, on which the first spring is disposed, by way of a third spring at above the first mass point,
a fourth mass point coupled to a surface opposite to a surface, on which the first spring is disposed, by way of a fourth spring at above the first mass point,
a fifth mass point coupled to a surface opposite to a surface, on which the second spring is disposed, in a direction opposing the third mass point by way of a fifth spring at above the second mass point,
a sixth mass point coupled to a surface on a side opposite to a surface, on which the second spring is arranged, by way of a sixth spring at above the second mass point,
wherein
a distance between the first mass point and the second mass point is simulated as a variable indicating the opening degree of the throat, and
a distance between the third mass point and the fifth mass point, and a distance between the fourth mass point and the sixth mass point are simulated as a variable indicating the opening degree of the vocal cord.
6 . The generation method of an audio signal according to claim 5 , further comprising:
receiving an instruction for setting to either a natural voice mode or a high voice mode; and
generating an audio signal in which levels of a first formant frequency, a second formant frequency, and a high-order integer order harmonic sound component are attenuated when receiving the instruction for setting to the high voice mode compared to when receiving the instruction for setting to the natural voice mode, an attenuation rate of the levels of the first formant frequency and the second formant frequency being lower than an attenuation rate of the level of the high-order integer order harmonic sound component,
wherein
the vocal cord model further simulates an inclusion of,
a seventh spring configured to couple the third mass point and the fourth mass point, and
an eighth spring configured to couple the fifth mass point and the sixth mass point, and
the natural voice mode and the high voice mode are switched by controlling at least spring constants of the seventh spring and the eighth spring.
7 . An audio synthesizing device comprising:
an input unit configured to input a plurality of variables including at least a first variable indicating an opening degree of a throat, which interiorly includes a vocal cord, with respect to a vocal cord model configured to output a second variable indicating an opening degree of the vocal cord according to reception of input of the plurality of variables; and
a generation unit configured to generate an audio signal in which a level of a non-integer order harmonic sound is changed, by controlling the second variable.