IBM has announced that they are releasing 500 of their patents to the open development community.  Speech related ones are below:

  • US6199043 Conversation management in speech recognition interfaces
  • US5649060 Automatic indexing and aligning of audio and text using speech recognition
  • US5636325 Speech synthesis and analysis of dialects
  • US6185529 Speech recognition aided by lateral profile image
  • US5615299 Speech recognition using dynamic features
  • US5615296 Continuous speech recognition and voice response system and method to enable conversational dialogues with microprocessors
  • US5263117 Method and apparatus for finding the best splits in a decision tree for a language model for a speech recognizer
  • US5222146 Speech recognition apparatus having a speech coder outputting acoustic prototype ranks

See: and for a list of patents.