US Patent 7319958 Polyphone network method and apparatus

Acoustic phones (preferably drawn 12 from a plurality of spoken languages) are provided 11. A hierarchically-organized polyphone network (20) organizes views of these phones of varying resolution and phone categorization as a function, at least in part, of phonetic similarity (14) and at least one language-independent phonological factor (15). In a preferred approach, a unique transcription system serves to represent the phones using only standard, printable ASCII characters, none of which comprises a special character (such as those characters that have a command significance for common script interpreters such as the UNIX command line).