Synthesis-based pre-selection of suitable units for concatenative speech

• US 7,013,278 B1
• Filed: 09/05/2002
• Issued: 03/14/2006
• Est. Priority Date: 07/05/2000
• Status: Expired due to Term

• Current Assignee: Cerence Operating Company (Cerence Inc.)
• Original Assignee: AT&T Corporation (AT&T, Inc.)
• Inventors: Conkie, Alistair D.
• Primary Examiner(s): MCFADDEN, SUSAN IRIS
• Application Number:
  US10/235,401
• Time in Patent Office: 1,286 Days
• Field of Search: 704/258, 704/260, 704/268, 704/270
• US Class Current: 704/260
• CPC Class Codes: G10L 13/07 Concatenation rules

Abstract

A method for generating concatenative speech uses a speech synthesis input to populate a triphone-indexed database that is later used for searching and retrieval to create a phoneme string acceptable for a text-to-speech operation. Prior to initiating the “real time” synthesis process, a database is created of all possible triphone contexts by inputting a continuous stream of speech. The speech data is then analyzed to identify all possible triphone sequences in the stream, and the various units chosen for each context. During a later text-to-speech operation, the triphone contexts in the text are identified and the triphone-indexed phonemes in the database are searched to retrieve the best-matched candidates.

Claims

1. A method of synthesizing speech from text using a triphone unit selection database, the method comprising:

receiving input text;

selecting a plurality of N phoneme units from the triphone unit selection database as candidate phonemes for synthesized speech based on the input text;

applying a cost process to select a set of phonemes from the candidate phonemes; and

synthesizing speech using the selected set of phonemes.

2. The method as defined in claim 1 wherein a Viterbi search is applied as the cost process.

3. The method as defined in claim 1 wherein subsequent to the step of receiving the input text the following step is performed:

parsing the received text into recognizable units.

4. The method as defined in claim 3 wherein the parsing comprises the steps of:

applying a text normalization process to parse the received text into known words and convert abbreviations into known words; and

applying a syntactic process to perform a grammatical analysis of the known words and identify their associated part of speech.