JPH10333695A - Voice converting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the clearness and hearing easiness of a gullet-pronounced voice, by detecting the zero intersection of the inputted voice, calculating the power of the voice, and amplitude-emphasizing the voice for every detected zone with a zero intersection detecting means. SOLUTION: The voice inputted from a voice input end 1 (such as a microphone) is A/D-converted by an A/D-converter 2 and accumulated in a wave-form memory section 3. A zero intersection detection section 4 detects the zero intersection of the accumulated voice wave-form and determines the processing zone. A power calculation section 5 obtains the power (amplitude square sum) of the wave-form in the processing zone. A power comparison section 6 compares the obtained power value with a threshold value set in advance. When the power value is larger than the threshold value, an amplitude emphasis section 7 conducts an amplitude emphasis processing. When the power value is smaller than the threshold value, no amplitude emphasis processing is conducted, and the voice is outputted to a voice output end 9 (such as a speaker) as it is via a D/A-converter 8. The inputted voice is A/D-converted, the zero intersection is detected, and the amplitude emphasis processing is conducted for the zone.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voice conversion apparatus for processing input voice and outputting the processed voice with improved clarity and audibility.

[0002]

2. Description of the Related Art A patient who has undergone pharyngectomy surgery using a laryngeal cancer loses its voice. However, it is possible to produce a voice by training an esophageal vocalization method in which the esophagus is vibrated instead of the vocal cords. However, the esophagus uttered voice has the following problems.・ Insufficient volume of exhalation causes a loud or no faint voice.・ The fundamental frequency is low and disturbed.・ There is much noise such as stomatal noise.

[0003] In order to improve the problem of loudness, analog loudspeakers and the like are sold, but they are not sufficiently useful because they loudspeakers including noise.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to alleviate the problem of esophageal utterance voice described in the section of the prior art.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a voice input means for inputting voice, an A / D conversion means for input voice, and a voice for storing input voice. An audio conversion device includes a storage unit, a unit for detecting a zero-crossing point of an input voice, a unit for calculating the power of the voice, and a unit for performing amplitude emphasis for each section detected by the zero-crossing detection unit.

[0006] Also, a voice input means for inputting voice, a means for AD converting the input voice, a voice storage means for storing the input voice, a means for detecting a fundamental frequency of the input voice, and a voice And a means for performing amplitude emphasis for each fundamental period detected by the fundamental frequency detecting means.

[0007] Further, a voice input means for inputting voice, a means for AD converting the input voice, a voice storage means for storing the input voice, a means for detecting a zero crossing point of the input voice and an amplitude. Is a voice conversion device having a loudspeaker for multiplying the constant by a factor, a calculator for calculating the power of the voice, and a unit for emphasizing the amplitude for each section detected by the zero-crossing detector.

[0008] Also, there are voice input means for inputting voice, means for AD converting input voice, voice storage means for storing input voice, and means for detecting a zero crossing point of input voice. This is a voice conversion device having means for judging sound / silence and means for performing amplitude emphasis for each section detected by the zero-crossing detecting means.

Also, a voice input means for inputting voice, a means for AD-converting the input voice, a voice storage means for storing the input voice, a means for detecting a zero crossing point of the input voice, and a voiced voice / A voice conversion device having means for determining unvoicedness and means for performing amplitude emphasis for each section detected by the zero-crossing detection means.

[0010] Also, voice input means for inputting voice, means for A / D conversion of input voice, voice storage means for storing input voice, means for detecting a zero crossing point of input voice, and voice And a means for performing amplitude emphasis for each section detected by the zero-crossing detecting means, and a means for analyzing speech, and a parameter used for amplitude emphasis is determined by the analyzing means. .

(Operation) According to the above configuration, the input voice is A / D converted, a zero-crossing point is detected, and amplitude emphasis processing is performed in that section, whereby the clarity of the esophageal voice is improved.
Listenability can be improved.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) FIG. 1 is a block diagram of one embodiment of the present invention described in claim 1. A sound input from a sound input terminal 1 (such as a microphone) is A / D converted by an A / D converter 2 and stored in a waveform storage unit 3. Reference numeral 4 denotes a zero-crossing detecting unit which detects a zero-crossing point of the stored speech waveform and determines a processing section. The power calculator 5 calculates the power (sum of amplitude squared) of the waveform in the processing section. The power value obtained by the power comparing section 6 is compared with a preset threshold value. When the power value is larger than the threshold value, the amplitude emphasizing section 7 performs amplitude emphasis processing. When the power value is smaller than the threshold value, the signal is output to the audio output terminal 9 (such as a speaker) via the D / A converter 8 without performing the amplitude emphasis processing.

Next, each processing will be described in detail. FIG.
FIG. 1 is a schematic diagram for explaining the present invention. The vertical axis represents the amplitude and the horizontal axis represents the time, and the input speech waveform is shown.
The input voice is digitized by the A / D converter 2 and converted into a sequence, x (1), x (2), x (i),.
Is accumulated in In the zero-crossing detection unit 4, the speech waveform x (i-
1) Detect a point (zero crossing point) where the sign of x (i) is different. After the first zero-crossing point t0 is detected, the next zero-crossing point t1 is detected after a lapse of a predetermined interval (2 ms in this embodiment: 20 samples at a sampling frequency of 10 KHz). Similarly, t2 is detected.

The sections are represented as T0 "t0-t1" and T1 [t1-t2] The power calculator 5 calculates the power of the waveform for each section by the following equation.

[0015] When the obtained P (TO) is smaller than the preset threshold value Pmin, the section is determined to be noise, and the amplitude emphasis processing is not performed. When P (T0)> Pmin, the S amplitude emphasizing section 7 performs amplitude emphasis by the following equation.

Xmax (T0): Maximum value of waveform in section T0 Xmax: Maximum value of amplitude enhancement (preset) r: Ratio of amplitude enhancement (preset) α (T0): Amplitude enhancement coefficient y (i in section T0 ): Waveform subjected to amplitude emphasis processing α (T0) = (Xmax−Xmax (T0)) * r / Xmax (t0) +1 Equation (2) y (i) = α (T0) * x (i) Equation (3) (Note: * indicates multiplication.) In this embodiment, A / D sampling is performed at 16 bits and 10 KHz, and Pmin = 50 and Xmax = 819.
2. Set r = 0.2.

FIG. 2 shows the input speech waveform by a solid line and the amplitude-emphasized waveform by a dotted line. FIG. 3A shows a speech waveform uttered by the esophagus speaker as “planting”, and FIG. 3B shows a waveform subjected to amplitude emphasis according to the present invention. As can be seen from FIG. 3, the "ru" part, which was hardly heard in the input voice, is emphasized, and the clarity of the processed voice is greatly improved.

In order to confirm the effects of the present invention, an evaluation test was performed by a paired comparison of Scheffe. (For paired comparisons of Scheffe, see Nikka Giren: Sensory test handbook
It is detailed on pages 356-384. 5) The original voice and the voice whose amplitude was emphasized according to the present invention were continuously presented to five subjects who were unfamiliar with the esophageal voice, and which was clear and easy to hear was evaluated on a five-point scale. The number of evaluation sentences is 4. Analysis of variance showed the effectiveness of the method of the present invention with a 1% risk factor.

(Embodiment 2) FIG. 4 is a block diagram of an embodiment of the present invention according to claim 2. The components having the same functions as those in the first embodiment are given the same numbers, and the description thereof is omitted. A fundamental frequency (pitch) detector 10 is provided in place of the zero-crossing detector of the first embodiment. In the first embodiment, the amplitude enhancement is performed on the section detected by the zero crossing.
In this embodiment, the operation is performed for one pitch section. Regarding the method of fundamental frequency extraction, various methods are already widely known.

As in the first embodiment, in the present invention, the clarity and audibility of the esophageal voice can be improved.

(Embodiment 3) FIG. 5 is a block diagram of an embodiment of the present invention according to claim 3. The components having the same functions as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted. In addition to the configuration of the first embodiment, a loudspeaker 11 exists between the zero-crossing detector 4 and the power calculator 5. In loudspeaker 11,
The input speech waveform is amplified by the following equation.

X (i): input waveform y (i): output waveform α: magnification> 1 y (i) = α * x (i) Equation (4) In this embodiment, α = 1.5.

The esophageal utterance voice has insufficient expiratory volume,
Although the sound volume is often insufficient, according to this method, the loudspeaker voice can be significantly improved in clarity and audibility since the voice is amplified in advance and then the amplitude is further emphasized.

(Embodiment 4) FIG. 6 is a block diagram of an embodiment of the present invention according to claim 4. The components having the same functions as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted. Instead of the power calculation unit and the power comparison unit of the first embodiment,
A sound / non-sound determining unit 12 is provided. In the first embodiment, whether or not to perform the amplitude emphasizing process is determined based on the power. However, in the esophageal vocal sound, since the noise such as the breathing sound and the airway sound is large and the level is high, the noise is determined when the power alone is used. May be emphasized. In the present invention, in order to avoid this problem, amplitude emphasis processing is performed based on the result of the sound / non-sound (noise) determination. Sound /
In the present embodiment, the following method is used as a silence determination method.

(1) The power for each fixed period is obtained from the input voice, and when the power is equal to or less than the threshold value 1, it is determined that there is no sound (the first embodiment).
the same as).

(2) When the power is equal to or more than the threshold value 1 and equal to or less than the threshold value 2, an LPC cepstrum coefficient is calculated, a distance calculation is performed with respect to a template previously determined as noise, and if noise is determined, amplitude enhancement is performed. No processing is performed.

(3) If none of the above, amplitude emphasis processing is performed. Esophageal vocal sounds are often accompanied by noise, but according to the present invention, without emphasizing noise,
The clarity and audibility of the esophageal voice can be greatly improved.

In the present invention, sound / silence (noise)
Although the cepstrum distance is used as the determination method of the above, this does not restrict the present invention at all.

(Embodiment 5) FIG. 7 is a block diagram of an embodiment of the present invention according to claim 5. The components having the same functions as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted. Instead of the power calculation unit and the power comparison unit of the first embodiment,
A voiced / unvoiced determination unit 13 exists. In the first embodiment, whether or not to perform the amplitude emphasis processing is determined based on the power. However, if the unvoiced consonant is emphasized too much, it may be difficult to hear. In the present invention, in order to avoid this problem, voiced / unvoiced judgment is performed, and amplitude emphasis processing is performed based on the result. In this embodiment, the following method is used as a voiced / unvoiced determination method.

(1) The power for each fixed period is obtained from the input voice, and when the power is equal to or less than the threshold value 1, it is determined that there is no sound (the first embodiment).
the same as).

(2) When the power is equal to or larger than the threshold value 1, the primary L
The PC cepstrum coefficient is obtained, and when this value is equal to or less than the threshold value 3, it is determined to be a voiceless part, and the amplitude emphasis processing is not performed.

(3) If none of the above, amplitude emphasis processing is performed. As described above, according to the present invention, it is possible to avoid emphasizing unnecessary consonants, and to significantly improve the clarity and audibility of the esophageal utterance voice.

In the present invention, a first-order cepstrum coefficient is used as a voiced / unvoiced determination method, but this does not restrict the present invention.

(Embodiment 6) FIG. 8 is a block diagram of an embodiment of the present invention according to claim 6. The components having the same functions as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted. A voice analysis unit 14 and a coefficient determination unit 15 are provided in addition to the first embodiment. The preset value, the maximum value Xmax of the amplitude emphasis, and the ratio r of the amplitude emphasis described in the first embodiment are more effective when individually determined by the user.
Alternatively, even for the same user, it is more effective to change it according to the tone of the voice. In the present embodiment, at the time of voice analysis, the value of Xmax is determined by obtaining power, and at the same time, an amplitude emphasized sound is created for each value of r = 0.1, 0.2, 0.3 to 1.0, and the optimum r Determine the value.

In this embodiment, the speech analysis and coefficient setting functions are implemented as a form incorporated in the speech converter.
It is also possible to realize this function by separately realizing this function on a personal computer and setting only the obtained coefficients in the voice conversion device.

[0036]

As described above, according to the present invention, the clarity and audibility of the esophageal voice can be greatly improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a voice conversion device according to a first embodiment of the present invention;

FIG. 2 is a diagram for explaining an algorithm according to the first embodiment of the present invention;

FIG. 3 is a diagram showing an input waveform and an output waveform of the first embodiment of the present invention.

FIG. 4 is a configuration diagram of a voice conversion device according to a second embodiment of the present invention;

FIG. 5 is a configuration diagram of a voice conversion device according to a third embodiment of the present invention.

FIG. 6 is a configuration diagram of a voice conversion device according to a fourth embodiment of the present invention.

FIG. 7 is a configuration diagram of a voice conversion device according to a fifth embodiment of the present invention.

FIG. 8 is a configuration diagram of a voice conversion device according to a sixth embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 audio input terminal (microphone) 2 A / D 3 waveform storage unit 4 zero-crossing detection unit 5 power calculation unit 6 power comparison unit 7 amplitude emphasis unit 8 D / A 9 audio output terminal (speaker) 10 fundamental frequency detection unit 11 amplitude Extension unit 12 Voiced / unvoiced determination unit 13 Voiced / unvoiced determination unit 14 Voice analysis unit 15 Coefficient determination unit

Claims (6)

[Claims] 1. A voice input means for inputting voice, a means for AD converting input voice, a voice storage means for storing input voice, a means for detecting a zero crossing point of input voice, and a voice And a means for calculating the power of the signal, and a means for performing amplitude emphasis for each section detected by the zero-crossing detecting means. 2. A voice input means for inputting voice, a means for AD converting input voice, a voice storage means for storing input voice, a means for detecting a fundamental frequency of input voice, and a voice And a means for calculating the power of the fundamental frequency and a means for performing amplitude emphasis for each fundamental period detected by the fundamental frequency detecting means. 3. A voice input means for inputting voice, an A / D conversion means for input voice, a voice storage means for storing input voice, a means for detecting a zero crossing point of the input voice, and an amplitude. A voice conversion device comprising: a loudspeaker for multiplying a constant by a factor; a calculator for calculating the power of voice; and a unit for performing amplitude emphasis for each section detected by the zero-crossing detector. 4. A voice input means for inputting voice, a means for AD converting input voice, a voice storage means for storing input voice, and a means for detecting a zero crossing point of the input voice. A voice conversion apparatus comprising: means for determining sound / silence; and means for performing amplitude emphasis for each section detected by the zero-crossing detecting means. 5. Voice input means for inputting voice, means for AD converting input voice, voice storage means for storing input voice, means for detecting a zero crossing point of input voice, and voiced. A voice conversion apparatus comprising: means for determining unvoicedness; and means for performing amplitude emphasis for each section detected by the zero-crossing detecting means. 6. Voice input means for inputting voice, means for AD converting input voice, voice storage means for storing input voice, means for detecting a zero-crossing point of input voice, and voice. And a means for performing amplitude emphasis for each section detected by the zero-crossing detection means and a means for analyzing voice, wherein parameters used for amplitude emphasis are determined by the analysis means. Voice converter.