Method and system for preselection of suitable units for concatenative speech
AssigneeAT&T Intellectual Property II, L.P.
InventorAlistair D. Conkie
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Abstract
A system and method for improving the response time of text-to-speech synthesis utilizes “triphone contexts” (i.e., triplets comprising a central phoneme and its immediate context) as the basic unit, instead of performing phoneme-by-phoneme synthesis. The method comprises a method of generating a triphone preselection cost database for use in speech synthesis, the method comprising 1) selecting a triphone sequence u1-u2-u3, 2) calculating a preselection cost for each 5-phoneme sequence ua-u1-u2-u3-ub, where u2 is allowed to match any identically labeled phoneme in a database and the units ua and ub vary over the entire phoneme universe and 3) storing a group of the selected triphone sequences exhibiting the lowest costs in a triphone preselection cost database.
Claims15
A computing device that generates a database for use in speech synthesis, the computing device generating the database according to a method comprising:
- selecting a triphone sequence;
- calculating a preselection cost for each 5-phoneme sequence where a unit of the 5-phoneme sequence is allowed to match any identically labeled phoneme in a database and at least two units of the 5-phoneme sequence vary over the entire phoneme universe;
- and
- storing a group of the selected triphone sequences exhibiting the lowest costs in a triphone preselection cost database by:
- determining a plurality of N least cost database units for the particular 5-phoneme context;
- performing the union of the N least cost units for all combinations of the at least two units;
- storing the union created in the step of performing the union in the triphone preselection cost database;
- and
- repeating steps of selecting, calculating and storing a group of the selected triphone sequences for each possible triphone sequence.
A method for generating a triphone preselection cost database for use in speech synthesis, the method comprising, for each of plurality of triphone sequences:
- calculating a preselection cost for each 5-phoneme sequence, wherein a triphone sequence of the plurality of triphone sequences is included in each 5-phoneme sequence;
- storing a group of triphone sequences exhibiting the lowest costs in a triphone preselection cost database by:
- a) determining a plurality of N least cost database units for the particular 5-phoneme context:
- b) performing the union of the N least cost units for all combinations of two selected units from the 5-phoneme sequence;
- and
- c) storing the union created in step b) in the triphone preselection cost database.
A computer-readable medium storing instructions for controlling a computing device to generate a triphone preselection cost database for use in speech synthesis, the instructions comprising, for each of plurality of triphone sequences:
- calculating a preselection cost for each 5-phoneme sequence, wherein a triphone sequence of the plurality of triphone sequences is included in each 5-phoneme sequence;
- storing a group of triphone sequences exhibiting the lowest costs in a triphone preselection cost database by:
- a) determining a plurality of N least cost database units for the particular 5-phoneme context;
- b) performing the union of the N least cost units for all combinations of two selected units from the 5-phoneme sequence;
- and
- c) storing the union created in step b) in the triphone preselection cost database.
Dependencies are inferred from the claim text.