Text-to-speech synthesis with controllable processing time and speech quality

• US 5,615,300 A
• Filed: 05/26/1993
• Issued: 03/25/1997
• Est. Priority Date: 05/28/1992
• Status: Expired due to Fees

• Current Assignee: Toshiba Corporation
• Original Assignee: Toshiba Corporation
• Inventors: Nitta, Tsuneo, Hara, Yoshiyuki
• Primary Examiner(s): MacDonald, Allen R.
• Assistant Examiner(s): Sartori, Michael A.
• Application Number:
  US08/067,079
• Time in Patent Office: 1,399 Days
• Field of Search: 395/2.67, 395/2.69, 395/2.76, 395/2.77, 395/2, 395/2.4, 395/2.44, 395/2.73-2.75, 381/40, 381/51, 381/52
• US Class Current: 704/260
• CPC Class Codes: G10L 13/04 Details of speech synthesis systems, e.g. synthesiser structure or memory management
• CPC Class Codes: G10L 13/047 Architecture of speech synthesisers

Abstract

Synthesized speech is generated by a software-implemented system with a programmed central processing unit. Phonetic parameters are generated from a series of phonetic symbols of an input text to be converted into synthesized speech, and prosodic parameters are also generated from prosodic information of the input text. The activity ratio of the central processing unit is determined, and the order of phonetic parameters or the arrangement of a synthesis unit or filter for speech synthesis is determined depending on the determined activity ratio of the central processing unit. Synthesized speech sounds are generated and filtered based on the phonetic and prosodic parameters according to the determined order of phonetic parameters or the determined arrangement of the filter.

Claims

1. A method of synthesizing speech with a system having a programmed central processing unit, comprising the steps of:

generating phonetic parameters from a series of phonetic symbols of an input text;

generating prosodic parameters from prosodic information of the input text;

detecting an activity rate of the central processing unit;

determining a degree number of at least one particular phonetic parameter, each particular phonetic parameter having a different degree number in different contexts, depending on the detected activity rate of the central processing unit; and

generating and filtering synthesized speech sounds based on the phonetic and prosodic parameters including adapting the filtering according to the determined degree number of the particular phonetic parameter.

2. A method according to claim 1, wherein said input text has frames, accent phrases., pauses, sentences, and paragraphs, said activity rate of the central processing unit being detected in every frame, every accent phrase, every pause, every sentence, or every paragraph of the input text, or once at the beginning of the input text.

3. A method of synthesizing speech with a system having a programmed central processing unit, comprising the steps of:

generating phonetic parameters from a series of phonetic symbols of an input text;

generating prosodic parameters from prosodic information of the input text;

detecting an activity rate of the central processing unit;

determining a degree number of at least one particular phonetic parameter each particular phonetic parameter having a different degree number in different contexts, said degree number depending on said detected activity rate;

determining a synthesis unit from a plurality of synthesis units according to said particular phonetic parameter; and

generating and filtering synthesized speech sounds based on the phonetic and prosodic parameters according to the determined synthesis unit.

4. A method according to claim 3, wherein said input text has frames, accent phrases, pauses, sentences, and paragraphs, said activity rate of the central processing unit being detected in every frame, every accent phrase, every pause, every sentence, or every paragraph of the input text, or once at the beginning of the input text.

5. A method of synthesizing speech with a system having a programmed central processing unit, comprising the steps of:

generating phonetic parameters from a series of phonetic symbols of an input;

generating prosodic parameters from prosodic information of the input text;

detecting an activity rate of the central processing unit;

inputting information representative of a quality of synthesized speech sounds to be generated depending on the activity rate of the central processing unit;

determining a degree number of at least one particular phonetic parameter, each particular phonetic parameter having a different degree number in different contexts, said degree number being determined according to the input information; and

selecting a synthesis unit from among a plurality of synthesis units according to said degree number of said particular phonetic parameter during each one of a plurality of different periods of time; and

generating and filtering synthesized speech sounds based on the phonetic and prosodic parameters employing said selected synthesis unit.

6. A method according to claim 5, wherein said input text has frames, accent phrases, pauses, sentences, and paragraphs, said activity rate of the central processing unit being detected in every frame, every accent phrase, every pause, every sentence, or every paragraph of the input text, or once at the beginning of the input text.

7. An apparatus for synthesizing speech with a system having a programmed central processing unit, comprising:

means for generating phonetic parameters from a series of phonetic symbols of an input text;

means for generating prosodic parameters from prosodic information of the input text;

detector means for detecting an activity rate of the central processing unit;

control means for determining a degree number of at least one particular phonetic parameter, each particular phonetic parameter having a different degree number in different contexts, said degree number being determined depending on the detected activity rate of the central processing unit; and

speech synthesizer means for generating and filtering synthesized speech sounds based on the phonetic and prosodic parameters including adaptable filtering means and means for adapting the adaptable filtering means according to the determined degree number of the particular phonetic parameter.

8. An apparatus according to claim 7, wherein said input text has frames, accent phrases, pauses, sentences, and paragraphs, said detector means comprising means for detecting the activity rate of the central processing unit in every frame, every accent phrase, every pause, every sentence, or every paragraph of the input text, or once at the beginning of the input text.

9. An apparatus for synthesizing speech with a system having a programmed central processing unit, comprising:

means for generating phonetic parameters from a series of phonetic symbols of an input text;

means for generating prosodic parameters from prosodic information of the input text;

a plurality of synthesis units for effecting filtering during synthesis of speech sounds;

detector means for detecting an activity rate of the central processing unit;

means for determining a degree number of at least one particular phonetic parameter, each particular phonetic parameter having a different degree number in different contexts, said particular degree number depending on said detected activity rate;

selector means for selecting a respective one of said plurality of synthesis units according to said degree number of said particular phonetic parameter during each one of a plurality of different periods of time, a plurality of phonetic parameters and a plurality of prosodic parameters being generated during each one of said plurality of different periods of time; and

means including the selected synthesis unit for applying all said phonetic and prosodic parameters generated during each said one period of time to the respective one synthesis unit which is selected by said selector means to generate synthesized speech sounds.

10. An apparatus according to claim 9, wherein said input text has frames, accent phrases, pauses, sentences, and paragraphs, said detector means comprising means for detecting the activity rate of the central processing unit in every frame, every accent phrase, every pause, every sentence, or every paragraph of the input text, or once at the beginning of the input text.

11. An apparatus for synthesizing speech with a system having a programmed central processing unit, comprising:

means for generating phonetic parameters from a series of phonetic symbols of an input text;

means for generating prosodic parameters from prosodic information of the input text;

a plurality of synthesis units for effecting filtering during synthesis of speech sounds;

detector means for detecting an activity rate of the central processing unit;

means for determining a degree number of at least one particular phonetic parameter, each particular phonetic parameter having a different degree number in different contexts, said degree number depending on one of said detected activity rate and a quality of synthesized speech sounds to be generated;

selector means for selecting a respective one of said plurality of synthesis units according to said degree number of said particular phonetic parameter during each one of a plurality of different periods of time, a plurality of phonetic parameters and a plurality of prosodic parameters being generated during each one of said plurality of different periods of time; and

means including the selected synthesis unit for applying all of said phonetic and prosodic parameters generated during each said one period of time to the respective one synthesis unit that is selected by said selector means to generate synthesized speech sounds.

12. An apparatus according to claim 11, wherein said input text has frames, accent phrases, pauses, sentences, and paragraphs, said detector means comprising means for detecting the activity rate of the central processing unit in every frame, every accent phrase, every pause, every sentence, or every paragraph of the input text, or once at the beginning of the input text.

13. An apparatus for synthesizing speech with a system having a programmed central processing unit, comprising:

means for generating phonetic parameters from a series of phonetic symbols of an input text;

means for generating prosodic parameters from prosodic information of the input text;

input means for inputting information representative of a degree number of phonetic parameters in a first mode;

detector means for detecting an activity rate of the central processing unit in a second mode;

mode selector means for selecting one of said first and second modes;

control means for determining information representative of a degree number of at least one particular phonetic parameter, each particular phonetic parameter having a different degree number in different contexts, depending on the detected activity rate of the central processing unit; and

speech synthesizer means for generating and filtering synthesized speech sounds based on the phonetic and prosodic parameters according to the information input by said input means in said first mode selected by said mode selector means and according to the information determined by said control means in said second mode selected by said mode selection means.

14. An apparatus for synthesizing speech with a system having a programmed central processing unit, comprising:

means for generating phonetic parameters from a series of phonetic symbols of an input text;

means for generating prosodic parameters from prosodic information of the input text;

input means for inputting information representative of a quality of synthesized speech sounds to be generated in a first mode;

detector means for detecting an activity rate of the central processing unit in a second mode;

mode selector means for selecting one of said first and second modes;

control means for determining information representative of depending on the detected activity rate of the central processing unit; and

control means for determining information representative of a degree number of at least one particular phonetic parameter, each particular phonetic parameter having a different degree number in different contexts, depending on the detected activity rate of the central processing unit; and

speech synthesizer means for generating and filtering synthesized speech sounds based on the phonetic and prosodic parameters according to the information input by said input means in said first mode selected by said mode selector means and according to the information including said degree number determined by said control means in said second mode selected by said mode selector means.

15. An apparatus for synthesizing speech with a system having a programmed central processing unit, comprising:

means for generating phonetic parameters from a series of phonetic symbols of an input text;

means for generating prosodic parameters from prosodic information of the input text;

a plurality of synthesis units for effecting filtering on synthesized speech sounds for respective different periods of time;

input means for inputting information representative of one of said synthesis units in a first mode;

detector means for detecting an activity rate of the central processing unit in a second mode;

mode selector means for selecting one of said first and second modes;

means for generating a degree number of at least one particular phonetic parameter, each particular phonetic parameter having a different degree number in differing contexts, the degree number of said particular phonetic parameter depending on the detected activity rate of the central processing unit;

synthesis unit selector means for selecting said one of the synthesis units which is represented by the information input by said input means in said first mode selected by said mode selector means and for selecting one of the synthesis units depending on the the degree number of said particular phonetic parameter in said second mode selected by said mode selector means; and

speech synthesizer means for generating and filtering synthesized speech sounds based on the phonetic and prosodic parameters with said selected synthesis unit.