MOTIVATION FOR LEXICAL TREES


  • Multiple Pronunciations

  • Examples
    • Bill - "b ih l sp" and "b ih l sil"
    The - "dh iy" and "dh ah"

  • Duplication of phonetic contexts
  • Cross-word Triphones

  • Large number of triphones at word boundaries
  • Large vocabulary tasks create severe requirements
  • A priori network expansion works only on small tasks
  • Dynamic Network Expansion

  • Create triphones only as needed
  • Share contexts
    •