JPS5847719B2 - If you want to pose, please do so. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sentence-speech pause insertion method for inserting pauses between clauses during sentence-speech synthesis.

BACKGROUND ART Conventionally, various voice response services have used a recording and editing method using words or phrases as basic units.

In these methods, the recording time Scott is constant and the length of the recorded audio units is uneven, so the pauses that enter the output sentence audio will be of different lengths, giving the listener an unnatural feeling. It had the disadvantage of giving

Alternatively, a simple method of placing a pause of a certain length between each clause may be considered, but pauses are easy to insert where the syntactic connections between each clause are weak, and difficult where they are strongly connected. , Since there is a certain tendency to insert poses, it is not possible to obtain a natural feeling with fixed length poses.

Therefore, it is necessary to find a rule for inserting pauses between clauses so that they are as similar to natural speech as possible.

In consideration of the above points, the present invention uses sentence syntax information and phrase length information to insert and adjust the length of pauses between clauses in order to give naturalness to the sentence speech to be synthesized. This provides a method for automatically determining pauses in sentence speech.

Hereinafter, embodiments will be described in detail with reference to the drawings.

Figure 1 shows an implementation of a method for determining, when a character string of a sentence to be synthesized is given as input, whether a pause can be inserted between clauses in the sentence, and if a pause is inserted, its length. FIG. 2 is a block configuration diagram showing an example.

In FIG. 1, reference numeral 1 denotes an input terminal into which a string of characters and symbols representing a sentence to be synthesized is input, and is read by a 20-input symbol reading device.

3 is a word analyzer, and 4 is a word dictionary. The word analyzer 3 uses the word dictionary 4 to convert an input symbol string into a word sequence and outputs it.

5 is a phrase analyzer that combines word sequences and converts them into a phrase-based sequence.

A syntactic analyzer 6 performs syntactic analysis based on the output of the clause analyzer 5, or outputs the input sentence in the form of a dependency structure.

7 to 13 are pause insertion determining sections, which will be explained in detail later.

14 is an output terminal which outputs a sentence sequence including pause symbols and pause lengths.

The pause insertion method will be specifically explained below.

The first factor that determines the occurrence of pauses in sentence speech is the length of the phrases before and after the phrase of interest.

In other words, it is thought that after uttering a long speech, a pause occurs due to reasons such as being out of breath, and when a long phrase is about to be uttered, a pause is likely to occur in preparation.

Therefore, by keeping the structural connections of the sentences constant and focusing on a certain pose candidate point, we uttered sentences with various lengths of phrases before and after that point, and when we examined the pauses, we found that It has become clear that not only does the probability of inserting a pause increase as the length increases, but also that the relationship between the pause length and the length of the preceding and following phrases can be approximated by the following equation.

However, the length of a phrase is expressed by the number of moras.

Equation (1) means that as the length of the phrases before and after the pause increases, the length of the pause increases accordingly.

Further, equation (1) can be used as one evaluation function regarding whether or not to insert a pause.

The second factor that determines the occurrence of this pause is the syntactic position.

In other words, it is difficult to insert a pause in a position where the connection relationship between two sentence*clauses is strong, whereas it is easy to insert a pause in a position where the connection relationship is weak.

The degree of such a connection can be quantified using the depth of a node in a tree indicating the sentence structure of the pose candidate point of interest, or the case and modification relationships of preceding and following clauses, such as dependency structure.

Here, the simplest method is to set the lowest level of the syntax tree, that is, the clause level, as the first level, and set the clause level of the pose candidate point of interest to the highest level of Li1 as "m".
As ax, a quantity TL related to the degree of coupling is defined by the following equation.

It can be considered that the smaller the TLO value, the stronger the syntactic coupling.

FIG. 2 shows an example of a syntax tree.

In addition to this, as shown in Figure 3, based on the dependency structure of the sentence, the path from the target clause to the dependent clause (
It is also possible to express the degree of connection with connected clauses by the number of clauses.

In the following explanation, a method using the clause level of the syntax tree will be explained as an example.

Next, we will discuss a method for determining the pause of sentence speech using equation (1) and (Shiki).

A pause candidate point in a sentence can be expressed by a TL expressing the degree of connection between clauses at that point, and a pause insertion probability evaluation function L expressed by the following equation related to the lengths of the preceding and following clauses.

The function L is the product of the second term in equation (1).

FIG. 4 is a plane in which the above-mentioned TL and L are taken on the vertical and horizontal axes, respectively, and a certain pose candidate point corresponds to one point on this plane.

When we actually utter various sentences and check whether pauses are inserted, we find that this plane is divided into a region where pauses are inserted and a region where no pauses are inserted, and the two regions can be approximately separated by a straight line. .

In FIG. 4, reference numeral 15 indicates a region where a pose is included, 16 is a region where a pose is not included, and 17 represents a straight line separating the two regions.

This straight line is expressed by the following equation.

Here, γ, θ...constants, that is, the insertion of pauses in sentence speech, are determined by the balance between the degree of syntactic cohesion at the candidate point and the length of the preceding and following phrases. is equation (4).

As a result of the above, the following equation can be considered as a rule for inserting the pause length P.

The pause length when a pause is inserted is It is expressed as a constant multiple of γL.

TL+ FIG. 5 shows the relationship between TL+γL and insertion pause length.

The pause insertion method described above will be explained based on FIG.

It has already been mentioned that the structure of the input sentence is determined by the syntax analyzer 6, but if necessary, the case of each clause is also specified.

Further, a pose candidate point determiner 7 selects pose candidate points between each clause, and a clause connectivity degree calculation circuit 8 calculates the syntactic connectivity of each candidate point.

Here, it may be simply configured with a division circuit based on equation (2), but it is also possible to configure it with hardware that calculates more detailed function values using dependency distances and case relations. .

Next, the first candidate point counting from the beginning of the sentence is taken out, the phrase length measurement circuit 9 determines the length of phrases before and after the candidate point, and the function L calculation circuit 10 calculates equation (3) L. Ru.

This function L calculation circuit 10 includes an adder, a multiplier, a division circuit,
It consists of an index calculation circuit, etc.

The pause insertion determiner 11 includes an adder/multiplier and a threshold value determination circuit, and uses the output of the function L calculation circuit 10 and the output of the phrase connectivity degree calculation circuit 8 to determine whether or not to insert a pause.

If it is decided to insert a pause, its length is determined by the pause length calculation circuit 12, and the sentence end detection circuit 1
3, the pause symbol and pause length are output to the output terminal 14.

If no pause is inserted, the pause length calculation circuit 12 is skipped and the sentence end detection circuit 13 is entered.

When the end of sentence detection circuit 13 determines that the end of the sentence has not been reached, the pause candidate point is advanced by one and the phrase length measurement circuit 9 is activated again.
to go into.

The above operations are repeated until all pauses for the entire sentence are determined.

This table is [Example sentence, Taro Yamada is P1 Hurry P2 That P3
I climbed P4 to the mountain.

This is a comparison of an example in which the pause insertion method of the present invention is applied to the sentence P1, P2, P3.
, P4 indicates a pose candidate point, and the constants C, θ, and γ are, for example, C=225, θ-1.3, and γ-1.73.
I made it.

As explained above, the present invention analyzes the syntax of an input sentence,
However, this method determines whether or not to insert a pause and its length based on the strength of the connection between clauses at the candidate point for inserting a pause in the sentence audio and the length of the phrases before and after the clause.
When only the symbol sequence of a sentence is given as input, it is possible to automatically output pauses similar to those in natural speech, and by using the present invention, it is possible to automatically output pauses similar to those in natural speech. The present invention can provide a very useful sentence-speech pause insertion method that can add a sense of feeling.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a diagram showing an example of clause connectivity in a syntax tree, FIG. 3 is a diagram showing an example of dependency structure and dependency distance, and FIG. 5 is a diagram showing the distribution of the presence or absence of pauses in various sentence sounds, and FIG. 5 is a diagram showing an example of the relationship between pause length and parameters. 1... Input terminal, 2... Input symbol reading device, 3... Word analyzer, 4...
Word dictionary, 5... Phrase analyzer, 6...
Syntax analyzer, 7... Pose candidate point determiner, 8.
...Phrase connectivity degree calculation circuit, 9...Phrase length measurement circuit, 10...Function L calculation circuit, 11...
... Pause insertion determiner, 12 ... Pause length calculation circuit, 13 ... Sentence end detection circuit, 14 ...
...Output terminal.

Claims (1)

[Claims] 1. A means for analyzing the syntax of a sentence when the character symbols of a sentence are given as input in sentence phonetic synthesis;
A plane is constructed in which one axis is a function value indicating the distance between clauses determined from the structure of the syntax tree, and the other axis is a pause insertion probability evaluation function value whose variables are the lengths of clauses before and after the clause boundary, and means for determining whether or not to insert a pose by setting a pose insertion portion and a non-insertion portion on a straight line that bisects the plane, and determining a pose length based on the distance from the straight line that bisects the plane. Features a pause insertion method for sentence audio.