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Department of Linguistics

Context-Sensitive Rules (CSR)

Robert Mannell

The Grapheme-to-Phoneme process, as its name suggests, converts input text into a string of phonemes. What the GTP process does not do is to determine which non-contrastive variant of each phoneme, that is which allophone, will be selected for a given phonemic context. In other words, the exact realisation of each phoneme will depend upon the nature of the phonemes surrounding it and particularly upon the phonemes immediately adjacent to it.

In a TTS system that uses SBR, rather than concatenation, the CSR module is most likely closely related to the SBR module. In a TTS system that uses concatenation techniques, the CSR module is likely to control the selection of, for example, allophonic variants of diphones, demisyllables, etc.

  • For information on how MU-Talk's CSR module works, click here.