Method of controlling high-speed reading in a text-to-speech conversion system

• US 20030004723A1
• Filed: 01/29/2002
• Published: 01/02/2003
• Est. Priority Date: 06/26/2001
• Status: Active Grant

• Current Assignee: LAPIS Semiconductor Co., Ltd. (ROHM Co., Ltd.)
• Original Assignee: OKI Electric Industry Company Limited
• Inventors: Chihara, Keiichi
• Granted Patent: US 7,240,005 B2
• Time in Patent Office: Days
• 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 13/08 Text analysis or generation of parameters for speech synthesis out of text, e.g. grapheme to phoneme translation, prosody generation or stress or intonation determination

Abstract

A method of high-speed reading in a text-to-speech conversion system including a text analysis module (101) for generating a phoneme and prosody character string from an input text; a prosody generation module (102) for generating a synthesis parameter of at least a voice segment, a phoneme duration, and a fundamental frequency for the phoneme and prosody character string; and a speech generation module (103) for generating a synthetic waveform by waveform superimposition by referring to a voice segment dictionary (105). The prosody generation module is provided with both a duration rule table containing empirically found phoneme durations and a duration prediction table containing phoneme durations predicted by statistical analysis and, when the user-designated utterance speed exceeds a threshold, uses the duration rule table and, when the threshold is not exceeded, uses the duration prediction table to determined the phoneme duration.

Claims

1. A method of controlling high-speed reading in a text-to-speech conversion system including a text analysis module for generating a phoneme and prosody character string from an input text;

a prosody generation module for generating a synthesis parameter of at least a voice segment, a phoneme duration, and a fundamental frequency for said phoneme and prosody character string;

a voice segment dictionary in which voice segments as a source of voice are registered; and

a speech generation module for generating a synthetic waveform by waveform superimposition by referring to said voice segment dictionary,

said method comprising the step of providing said prosody generation module with a phoneme duration determination unit that includes both a duration rule table containing empirically found phoneme durations and a duration prediction table containing phoneme durations predicted by statistical analysis and determines a phoneme duration by using, when a user-designated utterance speed exceeds a threshold, said duration rule table and, when said threshold is not exceeded, said duration prediction table.

2. The method according to claim 1, wherein said threshold is a predetermined maximum utterance speed.

3. A method of controlling high-speed reading in a text-to-speech conversion system including a text analysis module for generating a phoneme and prosody character string from an input text;

a prosody generation module for generating a synthesis parameter of at least a voice segment, a phoneme duration, and a fundamental frequency for the phoneme and prosody character string;

a voice segment dictionary in which voice segments as a source of voice are registered; and

a speech generation module for generating a synthetic waveform by waveform superimposition while referring to said voice segment dictionary,

said method comprising the step of providing said prosody generation module with a pitch contour determination unit that has both an empirically found rule table and a prediction table predicted by statistical analysis and determines a pitch contour by determining both accent and phrase components with, when a user-designated utterance speed exceeds a threshold, said duration rule table and, when said threshold is not exceeded, said duration prediction table.

4. The method according to claim 3, wherein said threshold is a predetermined maximum utterance speed.

5. A method of controlling high-speed reading in a text-to-speech conversion system including a text analysis module for generating a phoneme and prosody character string from an input text;

a prosody generation module for generating a synthesis parameter of at least a voice segment, a phoneme duration, and a fundamental frequency for the phoneme and prosody character string;

a voice segment dictionary in which voice segments as a source of voice are registered; and

a speech generation module for generating a synthetic waveform by waveform superimposition by referring to said voice segment dictionary,

said method comprising the step of providing said prosody generation module with a sound quality coefficient determination unit that has a sound quality conversion coefficient table for changing said voice segment to switch sound quality and selects from said sound quality conversion coefficient table such a coefficient that sound quality does not change when a user-designated utterance speed exceeds a threshold.

6. The method according to claim 5, wherein said threshold is a predetermined maximum utterance speed.

7. A method of controlling high-speed reading in a text-to-speech conversion system including a text analysis module for generating a phoneme and prosody character string from an input text;

a prosody generation module for generating a synthesis parameter of at least a voice segment, phoneme duration, and fundamental frequency for the phoneme and prosody character string;

a voice segment dictionary in which voice segments as a source of voice are registered; and

a speech generation module for generating a synthetic waveform by waveform superimposition by referring to said voice segment dictionary,

said method comprising the step of providing said prosody generation module with both a pitch contour correction unit for outputting a pitch contour corrected according to an intonation level designated by the user and a switch for determining whether a base pitch is added to said pitch contour corrected according to said user-designated utterance speed.

8. The method according to claim 7, wherein said threshold is a predetermined maximum utterance speed.

9. The method according to claim 7, wherein said pitch contour correction unit performs a pitch contour generation process that includes a phrase component calculation process in which all phrases of an input sentence are processed by calculating a phrase component by statistical analysis according to said user-designated utterance speed or making said phrase component zero and a process in which all words in said input sentence are processed by calculating an accent component by statistical analysis according to said user-designated utterance speed and either correcting said accent component according to said user-designated intonation level or making said accent component zero.

10. A method of controlling high-speed reading in a text-to-speech conversion system including a text analysis module for generating a phoneme and prosody character string from an input text;

a prosody generation module for generating a synthesis parameter of at least a voice segment, a phoneme duration, and a fundamental frequency for said phoneme and prosody character string;

a voice segment dictionary in which voice segments as a source of voice are registered; and

a speech generation module for generating a synthetic waveform by waveform superimposition while referring to said voice segment dictionary,

said method comprising the step of providing said speech generation module with signal sound generation means for inserting a signal sound between sentences to indicate an end of a sentence when a user-designated utterance speed exceeds a threshold.

11. The method according to claim 10, wherein said threshold is a predetermined maximum utterance speed.

13. The method according to claim 12, wherein said threshold is a predetermined maximum utterance speed.

14. The method according to claim 12, wherein said phoneme duration determination unit performs a process in which when a word under process is a leading word in a sentence and said user-designated utterance speed exceeds said threshold, a phoneme duration is not corrected and, when said word under process is not a leading word of a sentence or said user-designated utterance speed does not exceed said threshold, a first process by which a phoneme duration correction coefficient is changed according to said user-designated utterance speed and a second process in which all syllables of said word are processed by correcting a length of a vowel or vowels of said word, and carrying out said first and second processes for all words contained in the sentence.

12. A method of controlling high-speed reading in a text-to-speech conversion system including a text analysis module for generating a phoneme and prosody character string from an input text;

a prosody generation module for generating a synthesis parameter of at least a voice segment, a phoneme duration, and a fundamental frequency for the phoneme and prosody character string;

a voice segment dictionary in which voice segments as a source of voice are registered; and

a speech generation module for generating a synthetic waveform by waveform superimposition by referring to said voice segment dictionary,

said method comprising the step of providing said prosody generation module with a phoneme duration determination unit for performing a process in which when a user-designated utterance speed exceeds a threshold, an utterance speed of at least a leading word in a sentence is returned to a normal utterance speed.