Patent ID: 6684187
Filing Date: 2004-01-27
Classification: G10L

Abstract:
A method of synthesizing speech from an input text using phonemes, the method comprising the steps:a) creating a triphone preselection cost database including a plurality of all likely triphone combinations and generating a key to index each triphone in the database, wherein creating the triphone preselection cost database further comprises: 1) selecting a predetermined triphone sequence u1-u2-u3; and 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 the database and the units ua and ub vary over the entire phoneme universe; b) retrieving a portion of the input text for synthesis as a phoneme sequence; c) comparing a retrieved phoneme, in context with its neighboring phonemes, with a plurality of N least cost triphone keys stored in the triphone preselection cost database; d) choosing, as candidates for synthesis, a list of units from the triphone preselection cost database that comprise a matching triphone key; e) repeating steps b) through d) for each phoneme in the input text; f) selecting the least cost path through the network of candidates; g) processing the phonemes selected in step f) into synthesized speech; and h) outputting the synthesized speech to an output device.