JP2008262120A - Utterance evaluation device and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an utterance evaluation device for evaluating quality of utterance about an arbitrary word string. <P>SOLUTION: The utterance evaluation device 1 of the invention includes: a storage means 3 for storing an evaluation word string list 3c, a language model, a pronunciation dictionary and a sound model; a large vocabulary continuous voice recognition means 8 for converting a voice data after voice recognition, to an utterance word string, and generating an analysis result of voice quality of the utterance word string; a display means 15 for displaying the analysis result; a highest similarity evaluation word string detecting means 11 for detecting the evaluation word string having a highest word similarity rate from the evaluation word string list 3c for the utterance word string; an utterance evaluation means 12 for generating an evaluation result about the utterance word string; and a display control means 17 for displaying the evaluation word string having the highest word similarity rate, and the evaluation result, on the display means 15, only when the word similarity rate exceeds a first threshold. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an utterance evaluation apparatus and an utterance evaluation program for realizing evaluation of speech quality, in particular speech training such as an announcer using the speech quality assessment, and entertainment for enjoying the speech quality as a game.

  Conventionally, an utterance evaluation apparatus and an utterance training apparatus that evaluate the quality of human utterances cause a user to utter specific word strings sequentially presented by the utterance evaluation apparatus, and the pronunciation, intonation, and utterance speed of the utterance. Etc. (see, for example, Patent Document 1, Patent Document 2, and Patent Document 3). However, these devices are modeled by storing information such as an announcer's voice and intonation as examples of utterances in advance and specifying the utterance content to the user. It was to compare the utterance and the user's utterance. Therefore, according to these devices, it is impossible to evaluate the utterance of any word string that the user wants to utter.

  For example, for announcement training to read stock prices clearly and at high speed, the user himself / herself could not make an evaluation by changing the utterance content by using an utterance evaluation device not designed for that purpose. In addition, these devices can provide utterance contents tailored to various user levels, such as children, young people, elderly people, elderly people, and announcers who have expertise in utterances in an environment where an unspecified number of users are expected. It has been difficult for the device itself to specify easily, and it has been difficult to apply it to an entertainment device that enjoys a good or bad utterance as a game.

  The conventional entertainment device that enjoys good and bad utterances as a game is designed to accept only the utterances of several answer candidates that are predetermined for each quiz by voice recognition, and the user wants to speak Is not accepted (see, for example, Patent Document 4).

  As a conventional device that evaluates arbitrary utterance contents, there is a device that evaluates only the utterance speed, but it does not evaluate the quality of pronunciation (see, for example, Patent Document 5, Patent Document 6, and Patent Document 7). In addition, these estimate the speech rate based only on the local acoustic features and do not use linguistic information at all, so the measurement error of speech rate is large, especially as an entertainment device. It is not suitable for applications that evaluate good or bad.

JP-A-11-143346 JP 2003-186379 A JP 2006-337667 A Japanese Patent Laid-Open No. 2002-159741 JP-A-5-289691 JP 7-295588 A JP 2005-331589 A

  An object of the present invention is to evaluate a predetermined word string (that is, an utterance word string to be described later) obtained by voice recognition of voice data directly or indirectly acquired for any word string that a user desires to utter. When it is similar to a word string, it is to provide an utterance evaluation apparatus and an utterance evaluation program that show more evaluation contents with higher accuracy and evaluate the quality of the utterance.

  An utterance evaluation apparatus according to the present invention is an utterance evaluation apparatus that analyzes and evaluates speech data, and includes an evaluation word string list including one or more predetermined evaluation word strings for evaluating speech data, a language model, and pronunciation Based on the language model, the pronunciation dictionary, and the acoustic model, the voice data is recognized and converted into an utterance word string based on the language model, the pronunciation dictionary, and the acoustic model, and based on the pronunciation dictionary and the acoustic model. A large vocabulary continuous speech recognition means for generating a sound quality analysis result of the utterance word string, a display means for displaying the analysis result, and the number of words that match the utterance word string in comparison with each word. The most similar evaluation word string detecting means for detecting from the evaluation word string list as the evaluation word string having the highest word similarity rate, and the utterance word string. Utterance evaluation means for generating an evaluation result including at least the highest word similarity and utterance speed, and an evaluation having the highest word similarity only when the highest word similarity exceeds a first threshold. Display control means for displaying a word string and the evaluation result on the display means.

  This makes it possible to confirm the utterance of any word string that the user wants to utter from various analysis results such as the speech recognition result word string, old voice waveform, voiceprint (spectrum), and intonation (intonation). It is possible to display the evaluation result such as the word similarity rate and the utterance speed on the display unit after determining whether or not the utterance content is similar to a predetermined evaluation word string. Many evaluation results can be provided.

  The utterance evaluation apparatus according to the present invention further includes language model weighting means for learning the language model using the evaluation word string included in the evaluation word string list, and the large vocabulary continuous speech recognition means has learned Voice data is converted into an utterance word string based on a language model.

  As a result, the evaluation word string list can be easily changed with respect to the utterance content desired by the user, and various levels of users from children to announcers who have expertise in utterance can use the utterance evaluation device as an utterance training device. Is possible.

  The utterance evaluation apparatus according to the present invention further comprises data management means for storing a correct word string that matches the utterance word string for each utterance of voice data in the storage means, and the language model weighting means includes the correct word A sequence is added to the evaluation word sequence list, and the language model is learned using the correct word sequence.

  Thus, even if a part of an arbitrary word string that the user wants to utter is not included in the language model created in advance or the list of evaluation word strings, the correct word string for each utterance ( The utterances of the arbitrary word string can be confirmed from various analysis results such as the word string of the speech recognition result and the acoustic score.

In the utterance evaluation apparatus according to the present invention, the utterance evaluation means further includes means for calculating a predetermined acoustic score and deriving pronunciation intelligibility by a weighted linear sum of the highest word similarity and the acoustic score. Have
The evaluation result further includes the pronunciation intelligibility.

  Thereby, the user can confirm the intelligibility of his / her pronunciation numerically.

  In the utterance evaluation device according to the present invention, the utterance evaluation means further includes means for storing the evaluation result as a history in the storage means, and whether or not the highest word similarity exceeds a second threshold value. A threshold determination unit that determines whether or not any of the evaluation results for the utterance word string indicates the highest value for the history when it is determined that the word similarity exceeds the second threshold. It is further characterized by further comprising a value determination means and a new recording achievement determination / notification means comprising a means for notifying the achievement of the new recording by voice or video when it is determined that the maximum value is indicated.

  Thereby, it is possible to realize an entertainment device that allows the user to enjoy good and bad utterances as a game, such as whether or not to speak fast and accurate words.

  Furthermore, the utterance evaluation program of the present invention includes a computer including a storage unit and a display unit, an evaluation word string list including one or more predetermined evaluation word strings for evaluating voice data, a language model, a pronunciation dictionary, and a sound. Based on the step of storing a model in the storage unit, and based on the language model, the pronunciation dictionary, and the acoustic model, speech data is recognized and converted into an utterance word string, and based on the pronunciation dictionary and the acoustic model A step of recognizing a large vocabulary continuous voice for generating a sound quality analysis result of the utterance word string, a step of displaying the analysis result on the display unit, and comparing the utterance word string for each word The most similar evaluation word string detection for detecting the evaluation word string having the largest number of matching words from the evaluation word string list as the evaluation word string having the highest word similarity rate. Generating an evaluation result including at least the highest word similarity rate and speaking rate for the utterance word string, and only if the highest word similarity rate exceeds a first threshold. And a step of displaying the evaluation word string having the word similarity rate and the evaluation result on the display unit.

  According to the present invention, for any word string that the user wants to speak, it is determined whether or not the utterance word string of the voice data directly or indirectly obtained is similar to a predetermined evaluation word string In addition, since the evaluation content is displayed on the display unit, the user can evaluate the quality of the utterance with higher accuracy and more evaluation content. In addition, according to the present invention, users of various utterance levels can use the game for utterance training, in which the user can flexibly change the utterance content, or from children to professional announcers regarding utterances. It is possible to provide an utterance evaluation apparatus or an utterance evaluation program that also functions as an entertainment apparatus or program that can be enjoyed as an entertainment program.

  Hereinafter, an utterance evaluation apparatus according to an embodiment of the present invention will be described in detail.

  In order to facilitate understanding of the speech evaluation apparatus according to the embodiment of the present invention, “character” means one character unit, and “word” means one term consisting of a combination of characters. In other words, the “word string” is a word that can be expressed as a single segment consisting of a combination of words. Note that “words” and “word strings” are at a level that can be processed in speech recognition, and are only distinguished for convenience of explanation, and are not required to be extremely strict. For example, when the word string “raw raw raw rice raw egg” (raw wheat), (raw rice), and (raw egg) are “words”, (raw), (wheat), (rice), and ( Egg) is the “character”. Further, the “evaluation word string” is a predetermined word string, and is used for comparison with a word string (a spoken word string described later) that has been voice-recognized. Further, the “uttered word string” refers to a word string obtained as a result of voice recognition of voice data by the large vocabulary continuous voice recognition means 8 described later. The “correct word string” refers to a word string having a content that matches the utterance word string voice-recognized by the large vocabulary continuous voice recognition means 8 described later.

  The “user” refers to a person who uses the utterance evaluation apparatus. “User voice data” refers to digital voice data of an arbitrary utterance section spoken by a user. “Reference voice data” refers to digital voice data of an arbitrary utterance section used as a reference, which is used to compare and evaluate digital voice data uttered by a user. This refers to digital speech data of an arbitrary utterance section uttered by an announcer having a proper ability.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing a functional configuration of an utterance evaluation apparatus according to an embodiment of the present invention. The utterance evaluation apparatus 1 includes a data input unit 2, a storage unit 3, a voice input unit 4, a control unit 16, and a display unit 15.

  The storage unit 3 includes voice data 3a composed of user voice data or reference voice data, language model, pronunciation dictionary, and acoustic model data (collectively referred to as voice recognition model data 3b), 1 An evaluation word string list 3c including one or more evaluation word strings, correct word string data 3d composed of arbitrary word strings, and history data 3e of utterance evaluation results are stored.

  The control unit 16 includes a data management unit 5, an utterance detection unit 6, a language model weighting processing unit 7, a large vocabulary continuous speech recognition unit 8, an analysis result display control unit 9, a recognition result word string display control unit 10, and a most similar evaluation word. It has a column detection unit 11, an utterance evaluation unit 12, a new record achievement determination / notification unit 13, a reference voice comparison unit 14, and a display control unit 17. Here, each of the most similar evaluation word string detection unit 11, the new record achievement determination / notification unit 13, the reference voice comparison unit 14, and the display control unit 17 displays the processing result of each unit on the display unit 15 as will be described later. It has a function to send to.

  The display unit 15 includes an analysis result display control unit 9, a recognition result word string display control unit 10, a most similar evaluation word string detection unit 11, a new record achievement determination / notification unit 13, a reference voice comparison unit 14, and a display control unit 17. Are displayed, that is, various analysis results 15a, recognition result word string 15b, most similar evaluation word string 15c, new record achievement notification 15e, reference voice comparison result 15f, and various utterance evaluation results 15d.

  Here, in order to function as the utterance evaluation apparatus 1, a computer can be preferably used. Such a computer includes a data management means 5, an utterance detection means 6, a language model weighting processing means 7, a large vocabulary continuous speech recognition. Means 8, analysis result display control means 9, recognition result word string display control means 10, most similar evaluation word string detection means 11, utterance evaluation means 12, new record achievement determination / notification means 13, reference voice comparison means 14, and display A control unit for causing the control means 17 to function can be realized by a central processing unit (CPU) (not shown), and the storage unit 3 can be constituted by at least one memory (not shown). The display unit 15 can be a display device such as a CRT or a liquid crystal display.

  Further, by causing such a computer to execute a predetermined program by the CPU, data management means 5, speech detection means 6, language model weighting processing means 7, large vocabulary continuous speech recognition means 8, analysis result display control means 9 , Functions of recognition result word string display control means 10, most similar evaluation word string detection means 11, utterance evaluation means 12, new record achievement determination / notification means 13, reference voice comparison means 14, and display control means 17 (described later) Function) can be realized. Furthermore, the data management means 5, the speech detection means 6, the language model weighting processing means 7, the large vocabulary continuous speech recognition means 8, the analysis result display control means 9, the recognition result word string display control means 10, and the most similar evaluation word string detection means 11. A program for realizing the functions of the speech evaluation means 12, the new record achievement determination / notification means 13, the reference voice comparison means 14, and the display control means 17 is stored in a predetermined area of the storage unit 3 (memory). Can be stored. Such a storage unit 3 can be composed of a RAM or the like inside the computer, or can be composed of an external storage device (for example, a hard disk). Further, such a program can be constituted by a part of software (stored in a ROM or an external storage device) on an OS used by a computer as the speech evaluation apparatus 1.

  Furthermore, a program for causing a computer that functions as the speech evaluation apparatus 1 to function as means as each component of the present invention can be recorded on a computer-readable recording medium.

  The data management means 5 stores each data (voice data 3a, voice recognition model data 3b, evaluation word string list 3c, and correct word string data 3d) input from the data input unit 2 in response to a user request. The data can be stored in the unit 3, and each data can be updated, changed, or learned according to a user's request. The data input unit 2 may be of any form such as a keyboard, a recording medium, and a microphone in a computer that functions as the speech evaluation apparatus 1.

  The utterance detection means 6 detects the utterance start point of the voice input from the voice input unit 4 in response to the user's request, and the voice data 3a (also referred to as the utterance section) until the utterance end point is detected. User voice data or reference voice data) is output to the large vocabulary continuous voice recognition unit 8. Note that the utterance detection unit 6 may detect an utterance section of the voice data 3 a (user voice data or reference voice data) stored in advance in the storage unit 3, and output it to the large vocabulary continuous voice recognition unit 8. . Further, the voice input unit 4 may be of any form such as a voice recording medium or a microphone in a computer that functions as the speech evaluation apparatus 1. Further, it is not necessary to input the user voice data and the reference voice data at the same time. In particular, the reference voice data can be sequentially stored in the storage unit 3 according to the user's request. As will be described later, this reference voice data is used when a comparison relating to sound quality such as voiceprint (spectrum) or intonation (intonation) is required, and is not necessarily required in the present invention. The user voice data or the reference voice data may be voice data for a word string included in the predetermined evaluation word string list 3c, or may be voice data for any other word string.

The large vocabulary continuous speech recognition means 8 includes a language model 3b ₁ previously learned from a considerable number of texts of various genres, a pronunciation dictionary 3b ₂ of tens of thousands to hundreds of thousands of words included in the language model 3b ₁ , Continuous voice of user voice data or reference voice data obtained from the utterance detection means 6 using the acoustic model 3b ₃ learned with a considerable number of voices by an unspecified number of speakers, including a professional announcer for utterances. Recognition (ie, character conversion) is processed almost in real time. The language model 3b ₁ , the pronunciation dictionary 3b ₂ and the acoustic model 3b ₃ are known to those skilled in the art and will be described in detail later. The large vocabulary continuous speech recognition means 8 generates various analysis results relating to the sound quality such as the waveform of speech data, voiceprint (spectrum), intonation (intonation), etc., for the detected utterance word string. Furthermore, the large vocabulary continuous speech recognition means 8 calculates the utterance speed of the detected utterance word string.

The language model weighting processing means 7 has a function of learning the language model 3b ₁ using the evaluation word strings included in the evaluation word string list 3c. Here, the weighting process by learning the language model will be described in detail later, but the connection height between words or characters, that is, the probability value is determined by learning, and the connection character or connected word is determined based on the learning result. This is a process of determining that there is. When to train a language model, the word evaluation word string within the evaluation word sequence list 3c, if there is no word corresponding to the pronunciation dictionary 3b _2, can be displayed on the display unit 15 to that effect to inform the user ( Not shown). The user can appropriately add data related to the pronunciation of the word to the pronunciation dictionary 3b ₂ via the data input unit 2. Due to the learning function of the language model weighting processing means 7, the large vocabulary continuous speech recognition means 8 can operate at a particularly high recognition rate when recognizing speech data of word strings included in the evaluation word string list 3c.

Here, the data management means 5 can store the correct word string 3d corresponding to each utterance in the storage unit 3 in response to a user request. In this case, the language model weighting processing means 7 adds the correct word string 3d to the evaluation word string list 3c and performs weighting so that a probability value larger than any word string in the evaluation word string list 3c is assigned as will be described later. Processing can be performed. Thereby, the large vocabulary continuous speech recognition means 8 is used when a part of an arbitrary word string that the user wants to speak is not included in the language model 3b ₁ or the evaluation word string list 3c created in advance. Even if it exists, it can be made to operate at a particularly high recognition rate by using the correct word string 3d for each utterance added to the evaluation word string list 3c.

  The analysis result display control means 9 displays analysis results about the utterance word string detected and analyzed by the large vocabulary continuous speech recognition means 8, for example, various analysis results 15a such as speech data waveform, voiceprint (spectrum), and intonation. It is displayed on the display unit 15 in almost real time. If it is the analysis result of the user voice data, the analysis result of the user's utterance will be displayed, and if it is the analysis result of the reference voice data, the analysis result of the sample voice will be displayed. As a result, the user can visually observe the difference between the two voices. As will be described later, the voice comparison means 14 can display the analysis result or evaluation result of both the user voice data and the reference voice data on the display unit 15.

  The recognition result word string display control means 10 displays the utterance word string detected by the large vocabulary continuous speech recognition means 8, that is, the recognition result word string 15b on the display unit 15 in almost real time. In the case of the utterance word string of the user voice data, the user's utterance word string is displayed. Thus, the user can observe the difference from the evaluation word string in the evaluation word string list 3c.

Preferably, the acoustic model 3b ₃ is previously learned by the data management means 5 using the reference voice data. Thereby, the reliability of the word string which is the recognition result of the large vocabulary continuous speech recognition means 8 is increased, and the user observes the recognition result word string 15b on the display unit 15 and recognizes his speech well and well. It becomes possible to confirm whether it was possible or not recognized well due to bad utterance.

Note that since the number of words that can be recognized by the large vocabulary continuous speech recognition means 8 is limited, a recognition error occurs when an unregistered word is generated, but as described above, the correct word string corresponding to each utterance By performing the weighting process of the language model 3b ₁ using 3d, the reliability of the word string of the recognition result can be increased.

  The most similar evaluation word string detection unit 11 receives an utterance word string (that is, the recognition result word string 15b) as a result of recognition by the large vocabulary continuous speech recognition unit 8, and the recognition result word string 15b is received as the evaluation word string list 3c. For each of the evaluation word strings, each word string is compared for each word or character, and the word string having the largest number of matching words or characters is referred to as the highest word similarity rate (hereinafter also referred to as the highest word similarity rate). ) As an evaluation word string. Further, when the highest word similarity rate is higher than a predetermined threshold value α, the most similar evaluation word string detection means 11 has an evaluation word string (hereinafter also referred to as the most similar evaluation word string) having the highest word similarity rate. It is determined that the voice is uttered, and the most similar evaluation word string 15 c is output to the display unit 15. However, since the voice data 3a is not necessarily an evaluation word string included in the evaluation word string list 3c, when the highest word similarity is lower than a predetermined threshold value α, the most similar evaluation word string 15c is not output.

  The utterance evaluation means 12 receives the value of the word similarity of the utterance word string (that is, the highest word similarity mentioned above) from the most similar evaluation word string detection means 11 and the corresponding utterance word from the large vocabulary continuous speech recognition means 8. Receives the speaking rate of the queue. Furthermore, the utterance evaluation means 12 calculates an acoustic score and pronunciation intelligibility, which will be described later, and generates at least one of word similarity, utterance speed, acoustic score, and pronunciation intelligibility as an evaluation result, and the evaluation result is It is sent to the display control means 17.

  The acoustic score is obtained by the following equation, for example.

Here, x _t is the acoustic feature quantity of the t-th frame of the input speech, μ _t is the average value of the t-frame of the acoustic model 3b ₃ learned in advance, and σ _t is the standard deviation representing the variance. Acoustic score 100 becomes when x _t coincides with mu _t, as the difference between _{x t} and mu _t widens, acoustic score approaches zero. For example, if t = 10 ms, an acoustic score for each frame of 10 ms unit is calculated, and for example, 100 acoustic scores can be obtained for an utterance for one second. The pronunciation intelligibility is obtained by the following equation, for example.

  Pronunciation intelligibility = k × word similarity + (1−k) × average acoustic score per frame / best acoustic score among all frames

  Here, the value of k is a weighting coefficient of 0 or more and 1 or less, and is experimentally determined in advance. The best acoustic score is the one closest to 100 among a plurality of acoustic scores.

  When the display control means 17 receives from the most similar evaluation word string detection means 11 that it is determined that the value of the word similarity of the utterance word string (that is, the above-mentioned highest word similarity) is higher than the predetermined threshold value α. In other words, various utterance evaluation results such as utterance speed, acoustic score, and pronunciation intelligibility are output to the display unit 15.

  When the new record achievement determination / notification unit 13 determines that the highest word similarity exceeds the second threshold, the threshold determination unit determines whether the word similarity exceeds the second threshold by the threshold determination unit. The highest value judging means for judging whether any of the evaluation results for the utterance word string shows the highest value for the history 3e, and when it is judged that the highest value is shown, the fact that the new record is achieved It is comprised from the means to notify with an audio | voice or an image | video. That is, the new record achievement determination / notification unit 13 receives the value of the highest word similarity from the most similar evaluation word string detection unit 11 (that is, from the evaluation result of the utterance evaluation unit 12), and the highest word similarity is predetermined. Any of the evaluation results of the utterance word string (for example, utterance speed, word similarity, pronunciation intelligibility, etc.) shows the highest value for the history 3e. In the case where the highest value is indicated, a new record achievement notification is given by displaying, for example, a sound such as a fanfare or a video of breaking a ball on the display unit 15, and the storage unit 3 (for example, history In 3e), the evaluation result relating to the new record is recorded or updated.

  Next, a detailed processing procedure of the speech evaluation apparatus will be described.

  FIG. 2 is a diagram illustrating a processing procedure in the speech evaluation apparatus according to the embodiment of the present invention. Hereinafter, the flow of processing will be described using a specific example.

  In step S1, the utterance detection means 6 is waiting for input of voice data. The storage unit 3 includes voice data 3a composed of user voice data or reference voice data, voice recognition model data 3b (language model, pronunciation dictionary, and acoustic model), and an evaluation including one or more evaluation word strings. The data management means 5 stores the word string list 3 c and correct word string data 3 d composed of arbitrary word strings in the storage unit 3. As described above, the history 3e of the speech analysis result and the speech evaluation result is stored in the storage unit 3, and the history 3e is updated as a function of the analysis result display unit 9 and the speech evaluation unit 12, and the data management unit 5 can be changed.

  In step S2, the utterance detection unit 6 detects the utterance start point and utterance end point of the user voice data or reference voice data from the voice input from the voice input unit 4, and specifies the utterance part (ie, utterance section). Then, the utterance part is sent to the large vocabulary continuous speech recognition means 8. In the utterance detection, based on the difference between the acoustic features of the human voice and the other acoustic features, only the human voice portion of the input speech is extracted as the utterance portion.

In step S3, the large vocabulary continuous speech recognition means 8 recognizes the speech data of the utterance part in the large vocabulary continuous speech. That is, the large vocabulary continuous speech recognition means 8 has a language model 3b ₁ learned in advance by a considerable number of texts of various genres, and a pronunciation dictionary 3b _{2 of} tens of thousands to hundreds of thousands of words included in the language model 3b _1. Then, the continuous speech recognition is processed in real time using the acoustic model 3b ₃ previously learned with a considerable number of voices of an unspecified number of speakers including a professional announcer for speech. Here, the large vocabulary continuous speech recognition means 8 determines the sound score of which word in the pronunciation dictionary 3b ₂ is similar to the pronunciation symbol of the word in the pronunciation dictionary 3b ₂ , and calculates the acoustic score with the acoustic model 3b ₃ corresponding to each pronunciation symbol. At the same time, a language score representing ease of connection between words is obtained from the language model, and a word string having the maximum sum of the acoustic score and the language score is output as a recognition result (recognition result word string 15b).

  Here, the large vocabulary continuous speech recognition means 8 and the language model weighting processing means 7 will be described in more detail. As shown in the processing samples of FIGS. 3A, 3B, and 3C, the evaluation word string list 3c includes, for example, “raw raw raw rice raw eggs” when the apparatus is used for the purpose of evaluating utterances of quick words. It is a list of multiple word strings, including quick words and the word string “Bus Gas Explosion” that is difficult for even announcers to speak.

For example, the language model weighting processing means 7 increases the probability value that the word “raw rice” is connected after the word “raw wheat” at a certain magnification, and performs weighting processing of the language model 3b ₁ used in the large vocabulary continuous speech recognition means 8. performs, for example, if the word "Namamugi" has not been registered in the pronunciation dictionary 3b _2, added to the pronunciation dictionary 3b ₂ pronunciation symbol strings / namamugi / a. As a result, when the utterance content of the voice data 3a matches or resembles the word string in the evaluation word string list 3c (for example, characters match at a predetermined rate or more), the speech data 3a operates at a particularly high recognition rate.

If, speech contents of the speech data 3a is, and if not fully learned in the language model 3b _1, rating if the word is not included in the column list 3c, as is the recognition rate decreases. Therefore, when the correct word string 3 d corresponding to each utterance is given by the data input means 2, the correct word string 3 d is temporarily stored in a predetermined area of the storage unit 3 by the data management means 5. The language model weighting processing means 7 adds the correct word string 3d to the evaluation word string list 3c in the storage unit 3. Furthermore, the language model weighting processing means 7 performs weighting processing of the language model 3b ₁ used by the large vocabulary continuous speech recognition means 8 so that a probability value larger than any word string in the evaluation word string list 3c is assigned. Thereby, the large vocabulary continuous speech recognition means 8 is a case where a part of an arbitrary word string that the user wants to speak is not included in the language model 3b ₁ or the evaluation word string list 3c created in advance. However, it operates with a particularly high recognition rate by using the correct word string 3d for each utterance and these phonetic symbol strings.

For example, the utterance content of the user voice data is “Daruma-san fell”, and this is added to the evaluation word string list 3c by the language model weighting processing means 7 as the correct word string 3d. For example, the language model weighting processing unit 7 may multiply the frequency value that the word “san” is connected to after the word “daruma” by a constant multiple so that the probability value that the word “san” is connected after the word “daruma” increases. By adding a constant, the weighting process of the language model 3b ₁ is performed. Further, the language model weighting processing means 7 adds the phonetic symbol string / daruma / to the function of the large vocabulary continuous speech recognition means 8 when the word “daruma” is not included in the pronunciation dictionary 3b _2. Execute.

  In step S4, the analysis result display control means 9 displays various analysis results 15a, for example, the waveform of the input speech obtained during the speech recognition process, voiceprint (spectrum), intonation (intonation), etc. on the display unit 15 in almost real time. To do. FIG. 4 shows a display example of the monitor screen of the display unit 15. When the voice data is user voice data, the analysis result of the user's utterance is displayed. When the voice data is reference voice data (for example, voice data by a specialist for a pre-recorded utterance), a model is displayed. As a result, the user can visually observe the difference between the two voices.

  In step S5, the recognition result word string display control means 10 further displays the utterance word string (that is, the recognition result word string 15b) as the recognition result of the large vocabulary continuous speech recognition means 8 on the display unit 15. As a result, the user can observe how the user voice data or the reference voice data is recognized.

  In step S6, the most similar evaluation word string detection means 11 compares each word string in the recognition result word string 15c and the evaluation word string list 3c, and detects an evaluation word string having the highest word similarity. In the large vocabulary continuous speech recognition means 8, for example, when the utterance “raw raw raw rice raw egg” of the input speech is correctly recognized as “raw raw raw rice raw egg” (FIG. 3A), When it is recognized as “egg” (FIG. 3B), or when it is recognized as “raw unreasonable garbage Nanata grandchild” (FIG. 3C), the most similar evaluation word string detection means 11 recognizes the recognition result word string 15c in each case. Are sequentially compared with “raw raw raw egg”, “your reporter has returned with a train”, “red roll paper blue roll yellow roll paper”, etc. included in the evaluation word string list 3c. calculate. The similarity ratio between two word strings can be efficiently calculated by a commonly used dynamic programming method. For example, as a recognition result of the large vocabulary continuous speech recognition means 8, when all characters are correct as shown in FIG. 3A, the word similarity is 100%, and when 5 characters out of 6 are correct as shown in FIG. 3B. The word similarity is 83.3%, and when one of the six characters is correct but one extra character is inserted as shown in FIG. 3C, the word similarity is 16.7%. .

  In step S7, when the most similar evaluation word string detection unit 11 determines that the detected highest word similarity rate is larger than a predetermined threshold value α (Y in step S7), evaluation is performed in step S8. Assuming that any word string in the word string list 3 c is uttered, the most similar evaluation word string 15 c is displayed on the display unit 15. Otherwise (N in step S7), the voice data 3a (that is, the recognition result word string 15b) is not included in the evaluation word string list 3c (or is not the correct word string 3d), and has any utterance content. If there is, the most similar evaluation word string 15c is not displayed. More specifically, for example, when the predetermined threshold value α is set to 30%, when the highest word similarity ratio is less than 30%, it is determined that the evaluation word string list 3c or the correct word string 3d is too different. That is, it is considered that the most similar evaluation word string does not exist in the evaluation word string list 3c as an utterance of an arbitrary word string. For example, when the predetermined threshold α is 30%, the processing sample examples 1 and 2 shown in FIGS. 3A and 3B respectively display the most similar evaluation word string 15c, but the processing sample example 3 shown in FIG. 3C. Then, the most similar evaluation word string 15c is not displayed.

  In step S9, the utterance evaluation means 12 further displays the utterance evaluation results such as the word similarity rate, utterance speed, and acoustic score of the recognition result word string 15b on the display unit 15. The speaking speed is obtained by dividing the number of phonemes in the most similar evaluation word string 15c by the speaking time. For example, as shown in Example 1 of the processing sample in FIG. 3A, when the recognition result for the utterance “raw raw raw rice raw egg” in the voice data 3 a is “raw raw raw rice raw egg”, the word similarity rate is 100% and the utterance time is 1 .5 seconds, 97 acoustic scores, etc. are displayed.

Similarly, as shown in Example 2 of the processing sample in FIG. 3B, when the recognition result is “raw wheat raw garbage raw egg”, the word similarity rate is 83.3%, the utterance time is 1.7 seconds, the acoustic score is 89 points, and the like. Is displayed. Acoustic score, the audio data 3a in large vocabulary continuous speech recognition means 8 (user voice data or reference audio data) can be calculated from the similarity between the acoustic model 3b _3. According to Equation (1), the pronunciation intelligibility can be calculated as 85.6 points from a word similarity rate of 83.3% and an acoustic score of 89 points when the weighting coefficient k is 0.6, for example.

  In step S10, the reference voice comparison means 14 compares and compares the analysis result by the analysis result display control means 9 and / or the result by the speech evaluation means 12 between the user voice data and the reference voice data. The comparison result 15f is displayed on the display unit 15. Thereby, the user can visually observe the difference between both analysis results and / or evaluation results.

  In step S11, the new record achievement determination / notification unit 13 causes the highest word similarity described above in step 7 to be equal to or higher than a predetermined threshold β (β> α) and the evaluation result of the corresponding evaluation word string (for example, , Utterance speed, word similarity rate, pronunciation intelligibility, etc.) is determined whether or not the recording data (for example, history 3e) stored in the storage unit 3 shows the highest value.

  In step S12, if any of the evaluation results (for example, speech rate, word similarity rate, pronunciation intelligibility, etc.) shows the highest value for the history 3e (Y shown in step S11), the new record is achieved. Is notified by voice or video. The new record achievement determination / notification means 13 preliminarily determines an evaluation result as a record achievement target, and stores and updates a list as a record achievement history in a predetermined area of the storage unit 3. Also good. For example, when the threshold β is set to 100%, the recognition result for the utterance “raw raw raw raw egg” in the voice data is “raw raw raw raw egg” and the word similarity rate is 100%. If the utterance can be uttered in a shorter time than the record of the shortest utterance time of “raw raw raw rice raw egg” in the list 3c of the evaluation word string, it is newly recorded that difficult words can be uttered accurately and quickly. The achievement is notified by video or sound, and the record is updated in a predetermined area of the storage unit 3 in the recording achievement history list (or history 3e).

  When the process of step S12 is completed, or when none of the evaluation results (for example, utterance speed, word similarity, pronunciation intelligibility, etc.) in the process of step S11 shows the highest value for the history 3e (N in step S11), the process returns to the voice data input waiting process in step S1, and the above-described steps are repeated in the same manner. If the user wants to finish the speech evaluation, the speech detection means 6 may be provided with a processing stop function so that the processing is finished.

  Thereby, according to the present embodiment, for any word string that the user wants to utter, the utterance word string of the voice data obtained directly or indirectly is similar to the predetermined evaluation word string It is possible to show more evaluation contents with higher accuracy and to evaluate the quality of the utterance. Also, as an utterance training device that allows users to flexibly change the utterance content, or as an entertainment device that allows users of various utterance levels to enjoy the quality of utterances as a game, from children to professional announcers A functioning speech evaluation device can be realized.

  Although the above embodiments have been described as representative examples, it will be apparent to those skilled in the art that many changes and substitutions can be made within the spirit and scope of the invention. For example, the above steps may not be executed depending on the application, or may be realized in a different order of steps. Furthermore, if a microphone is used for the data input unit, speech data can be evaluated in near real time for voice input as in the embodiment, but speech evaluation can also be performed on voice data recorded in advance on a voice recording medium. In addition, the utterance evaluation device described above allows users of various utterance levels to enjoy good or bad utterances as a game, from utterance training devices that allow users to flexibly change the content of utterances, and children to professional announcers. It is also possible to function as an entertainment device capable of Accordingly, the invention should not be construed as limited by the embodiments described above, but only by the claims.

  The utterance evaluation apparatus according to the present invention is useful in utterance tests, utterance training, or entertainment that enjoys utterances.

It is a figure which shows the function structure of the speech evaluation apparatus of the Example by this invention. It is a flowchart which shows the process sequence in the speech evaluation apparatus of the Example by this invention. It is a figure which shows the example of a process sample in the speech evaluation apparatus of the Example by this invention. It is a figure which shows the example of a process sample in the speech evaluation apparatus of the Example by this invention. It is a figure which shows the example of a process sample in the speech evaluation apparatus of the Example by this invention. It is a figure which shows the example of a display of the monitor screen of the display part in the speech evaluation apparatus of the Example by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Speech evaluation apparatus 2 Data input part 3 Storage part 4 Voice input part 5 Data management means 6 Speech detection means 7 Language model weighting processing means 8 Large vocabulary continuous speech recognition means 9 Analysis result display control means 10 Recognition result word string display control means 11 Most similar evaluation word string detection means 12 Utterance evaluation means 13 New record achievement determination / notification means 14 Reference voice comparison means 15 Display section 16 Control section 17 Display control means

Claims (6)

An utterance evaluation device that analyzes and evaluates speech data,
Storage means for storing an evaluation word string list including one or more predetermined evaluation word strings for evaluating voice data, and a language model, pronunciation dictionary, and acoustic model;
Based on the language model, the pronunciation dictionary, and the acoustic model, speech data is recognized and converted into an utterance word string, and the sound quality analysis result of the utterance word string is based on the pronunciation dictionary and the acoustic model. A large vocabulary continuous speech recognition means for generating
Display means for displaying the analysis result;
The most similar evaluation word string that detects the evaluation word string having the largest number of matching words for each word as the evaluation word string having the highest word similarity from the evaluation word string list. Detection means;
Utterance evaluation means for generating an evaluation result including at least the highest word similarity and utterance speed for the utterance word string;
Display control means for displaying the evaluation word string having the highest word similarity and the evaluation result on the display means only when the highest word similarity exceeds a first threshold;
An utterance evaluation apparatus comprising: Language model weighting means for learning the language model using the evaluation word string included in the evaluation word string list;
The utterance evaluation apparatus according to claim 1, wherein the large vocabulary continuous speech recognition means converts speech data into an utterance word string based on a learned language model. Data management means for storing in the storage means a correct word string that matches the utterance word string for each utterance of voice data;
The utterance evaluation apparatus according to claim 2, wherein the language model weighting unit adds the correct word string to the evaluation word string list and learns the language model using the correct word string. The utterance evaluation means further comprises means for calculating a predetermined acoustic score and deriving pronunciation intelligibility by a weighted linear sum of the highest word similarity and the acoustic score;
The utterance evaluation apparatus according to claim 1, wherein the evaluation result further includes the pronunciation intelligibility. The utterance evaluation means further includes means for storing the evaluation result in the storage means as a history,
Threshold determination means for determining whether or not the highest word similarity exceeds a second threshold, and when it is determined that the word similarity exceeds a second threshold, any of the evaluation results for the utterance word string is The highest value judging means for judging whether or not to show the highest value for the history, and the means for notifying the achievement of the new recording by voice or video when it is judged that the highest value is shown. The utterance evaluation apparatus according to claim 1, further comprising a new record achievement determination / notification unit. In a computer having a storage unit and a display unit,
Storing an evaluation word string list including one or more predetermined evaluation word strings for evaluating speech data, a language model, a pronunciation dictionary, and an acoustic model in the storage unit;
Based on the language model, the pronunciation dictionary, and the acoustic model, speech data is recognized and converted into an utterance word string, and the sound quality analysis result of the utterance word string is based on the pronunciation dictionary and the acoustic model. A large vocabulary continuous speech recognition step for generating
Displaying the analysis result on the display unit;
The most similar evaluation word string that detects the evaluation word string having the largest number of matching words for each word as the evaluation word string having the highest word similarity from the evaluation word string list. Detecting step;
Generating, for the utterance word string, an evaluation result including at least the highest word similarity and utterance speed;
Only when the highest word similarity exceeds a first threshold value, displaying the evaluation word string having the highest word similarity and the evaluation result on the display unit;
An utterance evaluation program to execute

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