JPH036518B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a plosive sound detection device for detecting plosive sounds.

Conventionally, there is no known method for reliably extracting plosive sounds from the characteristics of sounds picked up by a microphone using a normal method.

An object of the present invention is to provide a plosive sound detection device that reliably, simply, and in real time extracts plosive sounds from oral airflow information associated with speech.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the plosive sound detection device of the present invention.

In the figure, 1, 2, and 3 are oral airflow detectors that detect the flow velocity of the oral airflow and changes in the flow velocity (acceleration) during speech, and are composed of, for example, a hot wire wind velocity detector or a microphone with a windshield removed. be done. As shown in Fig. 2, these mouth airflow detectors 1, 2, and 3 detect the position of the maximum oral airflow velocity when the plosive p is uttered, respectively, at a distance in front of the speaker's mouth where the oral airflow accompanying speech can be detected. and the position of the maximum oral airflow velocity at the time of t speech, and the position of the maximum oral airflow velocity at the time of t speech. Numerals 4, 5 and 6 are determination circuits for determining whether or not the output signals of the oral air flow detectors 1, 2 and 3 have the characteristics of a plosive. It consists of a voltage comparison circuit that discriminates whether the magnitude exceeds a predetermined threshold.

7 is an OR circuit that outputs a plosive sound signal when any of the determination circuits 4, 5, and 6 outputs a signal indicating that it is a plosive sound, and the result of determining whether or not it is a plosive sound is determined from the output of the OR circuit. can be obtained.

Experiments have revealed that the oral airflow during plosive utterances has remarkable characteristics compared to the oral airflow during non-plosive utterances. For example, the flow velocity waveform of the oral airflow when a plosive is uttered has a pulse shape with a sharp rise in a direction specific to the type of plosive. On the other hand, the flow velocity waveform of the oral airflow during non-plosive speech is very small or has a gradual rise. FIG. 3A is a schema showing these situations, where a shows the plosive sound, and b and c show the oral airflow velocity waveforms when a non-plosive sound is uttered. Figure 3B is a diagram showing the acceleration of the oral airflow when uttering the plosive a' and the non-plosive sounds (b' and c'), and detects the output of the oral airflow detector that detects the acceleration or the oral airflow velocity. It is obtained by differentiating the output of the oral airflow detector using an electrical circuit. As is clear from FIG. 3B, a pulse-like waveform with a large amplitude is obtained for a plosive sound, and a waveform with a small amplitude is obtained for a non-plosive sound.

Furthermore, experiments have shown that the oral airflow signal unique to plosives can be obtained when the oral airflow detector is placed at a specific position determined by the type of plosive.

Figure 2b shows an example of the experimental results.
The distribution of oral airflow was measured when | or |ba|, |da|, and |ga| were uttered at a constant rate. Here, , and are the central axes of the oral airflow distribution for each plosive |p|, |b|, |k|, |g|, and |t|, |d| when the pronunciation point B is set to 0. The angles ∠XOA and ∠XOB from the horizontal axis are
and ∠XOC vary depending on the speaker, but are approximately 0° to 20°, 30° to 50°, and 50° to 70°, respectively. Oral airflow detection is therefore possible by placing the oral airflow detector approximately on these central axes.

Specifically, as shown in Figure 2 a, the plosive sound |
For p|, |b|, |k
|t|, |d at position 20 for |, |g|
For |, an oral airflow detector is placed at position 30. If the installation position of the oral airflow detector is deviated from the above-mentioned position, the output waveform obtained from the oral airflow detector during plosive utterances will no longer have the characteristic waveform shown in Figure 3 a or a', and will become a non-plosive sound. It is difficult or inaccurate to distinguish between If the aforementioned oral airflow detectors 1, 2, and 3 are used to detect the acceleration of the oral airflow, or if the oral airflow detection is passed through a differential circuit, the accuracy of detection is improved and the This allows for some leeway in placement.

FIG. 4 shows the output relationship of the oral airflow detector for each plosive sound. Here, a case is shown in which a device that detects the acceleration of the oral airflow or a device that detects the velocity of the oral airflow that includes a differential circuit is used as the oral airflow detector. As is clear from the figure, the plosive sounds |p|, |b| are detected by the oral airflow detector 1.
|k|, |g| are detected from 2, |t|, |d| are detected from 3, and the corresponding judgment circuits 4, 5, 6
will be judged. If the results shown in the figure are not obtained from any of the determination circuits, no output is generated from the OR circuit 7, and the sound is determined to be a non-plosive sound.

In the above explanation, three oral airflow detectors were used, but if it is necessary to take into account the relative positional deviation between the oral airflow detector and the mouth during use,
A plosive sound detection device can be constructed based on the same idea using three or more oral airflow detectors.

In the plosive sound detection device according to the present invention, a plurality of oral airflow detectors are installed at different positions, for example, 10, 20 and 30 in FIG. 2a. In such a configuration, when a word containing an arbitrary plosive is uttered, one of the plurality of mouth air flow detectors detects the mouth air flow specific to the plosive and outputs a specific signal.
This plosive-specific signal is determined to be a plosive by one of the determination circuits 4, 5, or 6, and the OR circuit 7 outputs a plosive signal.

As described above, according to the present invention, plosive sounds can be extracted reliably, easily, and in real time from oral airflow information accompanying speech.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the plosive sound detection device according to the present invention, FIG. 2 a is a diagram showing the arrangement of the mouth airflow detector in FIG. 1, and FIG. 2 b is a diagram showing the distribution of plosive sounds. 3 is a waveform diagram for explaining the operation of the embodiment shown in FIG. 1, and FIG. 4 is a diagram showing the relationship between a plosive sound and the output of the oral air flow detector shown in FIG. 1, 2, 3... Oral air flow detector, 4, 5, 6... Judgment circuit, 7... OR circuit.

Claims (1)

[Claims] 1 At the front of the mouth, 3 were installed at the position of the maximum oral airflow velocity during the plosive p utterance, the maximum oral airflow velocity during the k utterance, and the maximum oral airflow velocity during the t utterance.
three determination circuits for determining whether or not each output signal of the three oral air flow detectors has the characteristics of a plosive, and a A plosive sound detection device is comprised of an OR circuit that outputs a sum, and is characterized in that it detects plosive sounds from the characteristics of oral airflow when uttering a plosive sound.