SPEECH SYNTHESIS APPARATUS AND METHOD

• US 20080228487A1
• Filed: 02/22/2008
• Published: 09/18/2008
• Est. Priority Date: 03/14/2007
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Aizawa, Michio, Fukada, Toshiaki, Okutani, Yasuo
• Granted Patent: US 8,041,569 B2
• Time in Patent Office: Days
• US Class Current: 704/268
• CPC Class Codes: G10L 13/06 Elementary speech units used in speech synthesisers; Concatenation rules

Abstract

A language processing unit identifies a word by performing language analysis on a text supplied from a text holding unit. A synthesis selection unit selects speech synthesis processing performed by a rule-based synthesis unit or speech synthesis processing performed by a pre-recorded-speech-based synthesis unit for a word of interest extracted from the language analysis result. The selected rule-based synthesis unit or pre-recorded-speech-based synthesis unit executes speech synthesis processing for the word of interest.

Claims

1. A speech synthesis apparatus comprising:

language analysis unit configured to identify a word by performing language analysis on a supplied text;

a selection unit configured to select one of first speech synthesis processing of performing rule-based synthesis based on a result of the language analysis and second speech synthesis processing of performing pre-recorded-speech-based synthesis for playing back pre-recorded speech data as speech synthesis processing to be executed for a word of interest which is extracted from the result of the language analysis, wherein said selection unit selects the first or second speech synthesis processing based on a word adjacent to the word of interest;

a process execution unit configured to execute the first or second speech synthesis processing, which is selected by said selection unit, for the word of interest; and

an output unit configured to output synthetic speech generated by said process execution unit.

2. The apparatus according to claim 1, wherein said selection unit selects the same speech synthesis processing as the speech synthesis processing executed by said process execution unit previously for a word adjacent to the word of interest.

3. The apparatus according to claim 1, wherein said selection unit calculates concatenation distortion between synthetic speech of the word of interest upon selection of the first speech synthesis processing and synthetic speech of the adjacent word and concatenation distortion between synthetic speech of the word of interest upon selection of the second speech synthesis processing and synthetic speech of a word adjacent to the word of interest, and selects speech synthesis processing which minimizes concatenation distortion.

4. The apparatus according to claim 1, wherein said selection unit obtains a selection pattern of the first speech synthesis processing and the second speech synthesis processing for a word sequence identified in the solution in accordance with presence/absence of the pre-recorded speech data of each word, and selects one of the obtained selection patterns which minimizes a sum of the number of times of switching of the first speech synthesis processing and the second speech synthesis processing and the number of times of concatenation of words.

5. The apparatus according to claim 1, wherein said language analysis unit performs language analysis using a user dictionary capable of adding one of combinations of spelling information and pronunciation information, spelling information and pre-recorded speech, and spelling information, pronunciation information, and pre-recorded speech for a word associated with registration in accordance with an instruction from a user,

and wherein said process execution unit executes one of the first speech synthesis processing and the second speech synthesis processing which is selected by said selection unit for the word of interest based on the user dictionary.

6. The apparatus according to claim 5, wherein when the word of interest is a word registered in the user dictionary, said selection unit calculates waveform distortion between synthetic speech of the word of interest upon selection of the first speech synthesis processing and synthetic speech generated by performing pre-recorded-speech-based synthesis using the user dictionary upon selection of the second speech synthesis processing, and selects the second speech synthesis processing when the waveform distortion is larger than a threshold.

7. The apparatus according to claim 2, wherein

said language analysis unit includes an unit configured to determine whether each identified word is at a start of a breath group, and

upon selecting the first speech synthesis processing for the word of interest, said selection unit further selects the second speech synthesis processing for the word of interest when said language analysis unit determines that the currently processed word of interest is at a start of a breath group.

8. A speech synthesis method comprising:

a language analysis step of identifying a word by performing language analysis on a supplied text;

a selection step of selecting one of first speech synthesis processing of performing rule-based synthesis based on a result of the language analysis and second speech synthesis processing of performing pre-recorded-speech-based synthesis for playing back pre-recorded speech data as speech synthesis processing to be executed for a word of interest which is extracted from the result of the language analysis, wherein said selection step selects the first or second speech synthesis processing based on a word adjacent to the word of interest;

a process execution step of executing the first or second speech synthesis processing, which is selected in the selection step, for the word of interest; and

an output step of outputting synthetic speech generated in the process execution step.

9. A program stored on a computer-readable medium for causing a computer to execute a speech synthesis method defined in claim 8.

10. A computer-readable storage medium storing a program defined in claim 9.