Method for text-to-pronunciation conversion

• US 7,606,710 B2
• Filed: 12/21/2005
• Issued: 10/20/2009
• Est. Priority Date: 11/14/2005
• Status: Active Grant

• Current Assignee: Industrial Technology Research Institute
• Original Assignee: Industrial Technology Research Institute
• Inventors: Wang, Nien-Chih, Lee, Ching-Hsieh
• Primary Examiner(s): Sked; Matthew J
• Application Number:
  US11/314,777
• Publication Number:
  US 20070112569A1
• Time in Patent Office: 1,399 Days
• Field of Search: None
• US Class Current: 704/260
• 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 for text-to-pronunciation conversion includes a process for searching grapheme-phoneme segments and a three-stage process of text-to-pronunciation conversion. This method looks for a sequence of grapheme-phoneme pairs, which is referred to as a chunk, via a trained pronouncing dictionary, performs grapheme segmentation, chunk marking and a decision process on an input text, and determines a pronouncing sequence for the text. With the chunk marking, the method greatly reduces the search space on the associated phoneme graph, and thereby efficiently enhances the search speed for the candidate chunk sequences. The method keeps a high word-accuracy as well as saves computing time.

Claims

1. A method for text-to-pronunciation conversion in a text-to-pronunciation conversion system, comprising:

a chunk searching process performed in said text-to-pronunciation conversion system for finding a set of possible chunks via a trained pronouncing dictionary, a chunk being defined as a sequence of grapheme-phoneme pairs;

a grapheme segmentation process performed in said text-to-pronunciation conversion system for generating a grapheme sequence from an input text;

a chunk sequence marking process performed in said text-to-pronunciation conversion system for generating candidate chunk sequences of said input text from said grapheme sequence and said set of possible chunks; and

a decision process performed in said text-to-pronunciation conversion system for determining a pronouncing sequence for said input text by scoring said candidate chunk sequences of said input text;

wherein said decision process further includes a re-verifying process for a phoneme sequence by re-scoring said candidate chunk sequences according to characteristic combination of intra chunks and inter chunks.

2. The method for text-to-pronunciation conversion as claimed in claim 1, wherein a possible chunk in said chunk searching process is defined as a sequence of grapheme-phoneme pairs with length greater than one.

3. The method for text-to-pronunciation conversion as claimed in claim 1, wherein said chunk searching process adds a boundary symbol in a boundary location of a chunk in performing chunk searching.

4. The method for text-to-pronunciation conversion as claimed in claim 3, wherein adding a boundary symbol or not depends on pronunciation probability of a chunk being occurred on a boundary location.

5. The method for text-to-pronunciation conversion as claimed in claim 1, wherein said chunk searching process qualifies a chunk as a possible chunk when occurrence probability of the chunk is greater than a predetermined threshold, and the occurrence probability of the chunk is defined as a score of the chunk.

6. The method for text-to-pronunciation conversion as claimed in claim 1, wherein a scoring formula is used to evaluate a marking score for said chunk sequence marking process.

7. The method for text-to-pronunciation conversion as claimed in claim 1, wherein said decision process further performs score weight adjustment on scoring said candidate chunk sequences to determine a final pronunciation sequence for said input text.

8. The method for text-to-pronunciation conversion as claimed in claim 7, wherein a scoring formula is used to evaluate a marking score of said chunk sequence marking process.

9. The method for text-to-pronunciation conversion as claimed in claim 8, wherein a candidate chunk sequence with a highest score which accounts both said score weight adjustment and said marking score is nominated as the final pronunciation sequence for said input text.

10. The method for text-to-pronunciation conversion as claimed in claim 1, wherein said grapheme segmentation process uses an N-gram model to generate said grapheme sequence.

11. The method for text-to-pronunciation conversion as claimed in claim 1, wherein said decision process further includes a follow up evaluation with a scoring formula on scoring said candidate chunk sequences.

12. The method for text-to-pronunciation conversion as claimed in claim 1, wherein said text-to-pronunciation conversion method is applied in a text-to-pronunciation model for mobile information appliances.