Speech Recognition                     1
Introduction•   What is Speech Recognition?           - Voice Recognition?•   Where can it be used?    - Dictation    - Sy...
Contents:•   Continuous/Discrete•   How does it work?•   Recent improvements•   Current software options•   Future of SR  ...
Continuous or Discrete?    • Continuous speech       - dictation    • Discrete speech       - system controls             ...
How does SR work?  •   Recognition  •   Training  •   Correction  •   Command/Control                        5
Recognition (1)Voice Input     Analog to Digital      Acoustic Model                                       Language Model ...
Recognition (2)Acoustic Modeling• Spoken words: “I think there are…..”• Phonemes: ‘ ay th-in-nk-kd dh-eh-r aa-  r’• H.M.M....
Recognition (3)Language Modeling• Word context• Word frequency• Transition possibilities                         8
Voice Training (1)Can be done by:• Predetermined text segments• Individual wordsCompare new acoustic with old and combines...
Voice Training (2)User specific Voice file• Voice qualities• Pronunciation• Patterns of word use• Preferred vocabulary    ...
Making Corrections•   Move cursor by voice command•   Memorize edit commands•   List of possible alternatives•   Make corr...
Command/Control•   Desktop grid•   Program or Link name/number•   URL name•   Memorized commands                          12
Recent Improvements in SR  •   Faster training ~10 min.  •   Better recognition ~95%  •   More compatible software  •   Be...
Current Software Options for PC•   Dragon Systems – Naturally Speaking•   Philips – FreeSpeech•   IBM – ViaVoice•   Lernou...
How well do the work?           Training   Dictation App.        Command                      Correct. Integrat.    - Cont...
Future of SR• SUI – Speech-based User Interface• Improvements needed:  - Greater accuracy  - Greater system control/comman...
Conclusion•   SR Uses•   How does it work?•   Current Software•   Problems of SR•   More SR coming soon….                 ...
References• 1. Alwang, Greg. “Speech Recognition,” PC Magazine, December 1  1999• 2. Hauptmann, Alexander G. Jang, Photina...
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Speech recognition1

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Speech recognition1

  1. 1. Speech Recognition 1
  2. 2. Introduction• What is Speech Recognition? - Voice Recognition?• Where can it be used? - Dictation - System control/navigation - Commercial/Industrial applications - Hand held digital recorders 2
  3. 3. Contents:• Continuous/Discrete• How does it work?• Recent improvements• Current software options• Future of SR 3
  4. 4. Continuous or Discrete? • Continuous speech - dictation • Discrete speech - system controls 4
  5. 5. How does SR work? • Recognition • Training • Correction • Command/Control 5
  6. 6. Recognition (1)Voice Input Analog to Digital Acoustic Model Language Model Feedback Display Speech Engine 6
  7. 7. Recognition (2)Acoustic Modeling• Spoken words: “I think there are…..”• Phonemes: ‘ ay th-in-nk-kd dh-eh-r aa- r’• H.M.M.’s: 5 state representation• Speech Engine 7
  8. 8. Recognition (3)Language Modeling• Word context• Word frequency• Transition possibilities 8
  9. 9. Voice Training (1)Can be done by:• Predetermined text segments• Individual wordsCompare new acoustic with old and combines• More training = better recognition 9
  10. 10. Voice Training (2)User specific Voice file• Voice qualities• Pronunciation• Patterns of word use• Preferred vocabulary 10
  11. 11. Making Corrections• Move cursor by voice command• Memorize edit commands• List of possible alternatives• Make correction manually 11
  12. 12. Command/Control• Desktop grid• Program or Link name/number• URL name• Memorized commands 12
  13. 13. Recent Improvements in SR • Faster training ~10 min. • Better recognition ~95% • More compatible software • Better system control/command 13
  14. 14. Current Software Options for PC• Dragon Systems – Naturally Speaking• Philips – FreeSpeech• IBM – ViaVoice• Lernout & Hauspie – Voice Xpress 14
  15. 15. How well do the work? Training Dictation App. Command Correct. Integrat. - ControlDragon Excellent Excellent Good GoodPhilips Fair Fair Good GoodIBM Excellent Good Good ExcellentL&H Good Good Good Good 15
  16. 16. Future of SR• SUI – Speech-based User Interface• Improvements needed: - Greater accuracy - Greater system control/command - More compatible software 16
  17. 17. Conclusion• SR Uses• How does it work?• Current Software• Problems of SR• More SR coming soon…. 17
  18. 18. References• 1. Alwang, Greg. “Speech Recognition,” PC Magazine, December 1 1999• 2. Hauptmann, Alexander G. Jang, Photina Jaeyun. Carnegie Mellon University. “Learning to Recognize Speech by Watching Television,” IEEE Intelligent Systems, September/October 1999.• 3. Miastkowski, Stan. “Latest Speech Software Gets You Up and Running Faster,” PC World, November 1999. 18

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