Method for text-to-pronunciation conversion

• US 20070112569A1
• Filed: 12/21/2005
• Published: 05/17/2007
• 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
• Granted Patent: US 7,606,710 B2
• Time in Patent Office: Days
• 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

Disclosed is a method for text-to-pronunciation conversion, which comprises 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 (a sequence of grapheme-phoneme pairs is referred to a chunk) via a trained pronouncing dictionary, proceeds 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 invention, greatly reduces the search space on the associated phoneme graph, thereby efficiently enhances the search speed for the candidate chunk sequences. The invention keeps a high word-accuracy as well as saves lots of computing time. It is applicable to the audio-related products for mobile information appliances.

Claims

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

a grapheme-phoneme pair sequence (chunk) searching process, and

a three-stage text-to-pronunciation conversion process;

via a trained pronouncing dictionary, said method looks for a sequence of grapheme-phoneme pairs (a sequence of grapheme-phoneme pairs is referred to a chunk), and proceeds a grapheme segmentation procedure, a chunk marking process and a decision process on an input text, and determines a pronouncing sequence for said input text.

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

3. The method for text-to-pronunciation conversion as claimed in claim 2, wherein said grapheme-phoneme pair sequence searching process is a design by adding a boundary symbol and performs chunk searching.

4. The method for text-to-pronunciation conversion as claimed in claim 3, wherein said adding of said boundary symbol depends on the pronunciation probability of said chunk occurrence on boundary locations.

5. The method for text-to-pronunciation conversion as claimed in claim 2, wherein said grapheme-phoneme pair sequence searching process further comprising:

when the occurrence probability of said grapheme-phoneme pair sequence is greater than a predetermined threshold, said chunk is qualified as a candidate, and the score of said chunk is determined by said occurrence probability of said chunk.

6. The method for text-to-pronunciation conversion as claimed in claim 1, wherein said three-stage text-to-pronunciation conversion process includes:

performing said grapheme segmentation to the input text and generating a grapheme sequence;

performing said chunk marking process according to said grapheme sequence and the obtained said chunk set, and resulting in a set of N candidate chunk sequences, where N is a natural number; and

performing said decision process on said set of candidate chunk sequences,

performing further score weight adjustment and determining a final pronunciation sequence for said input text.

7. The method for text-to-pronunciation conversion as claimed in claim 6, wherein after said chunk marking process, an evaluation with a scoring formula is performed on said chunk marking.

8. The method for text-to-pronunciation conversion as claimed in claim 6, wherein said grapheme segmentation procedure uses an N-gram model to generate said grapheme sequence.

9. The method for text-to-pronunciation conversion as claimed in claim 6, wherein, said decision process further includes a follow up evaluation with a scoring formula to said decision process.

10. The method for text-to-pronunciation conversion as claimed in claim 6, wherein said, said decision process is performed by re-verifying said phoneme sequence for said N chunk sequences and re-scoring and re-verification for said N chunk sequences.

11. The method for text-to-pronunciation conversion as claimed in claim 10, wherein said re-verifying process for a phoneme sequence is re-scoring said N chunk sequences according to the characteristic combination of intra chunks and inter chunks.

12. The method for text-to-pronunciation conversion as claimed in claim 11, wherein, said score weight adjustment is done, to said chunk marking, by a scoring formula, with joint accounting of said weight adjustment and said re-verification scores, a resulting pronunciation sequence is nominated by said chunk sequence with the highest score.

13. The method for text-to-pronunciation conversion as claimed in claim 1, wherein said text-to-pronunciation conversion method is applicable to the text-to-pronunciation model for mobile information appliances.