1. 1 Speech Recognition

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

3. 3 Contents: Continuous/Discrete How does it work? Recent improvements Current software options Future of SR

4. 4 Continuous or Discrete? Continuous speech - dictation Discrete speech - system controls

5. 5 How does SR work? Recognition Training Correction Command/Control

6. 6 Recognition (1) Voice InputAnalog to DigitalAcoustic Model Language Model DisplaySpeech EngineFeedback

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

8. 8 Recognition (3) Language Modeling Word context Word frequency Transition possibilities

9. 9 Voice Training (1) Can be done by: Predetermined text segments Individual words Compare new acoustic with old and combines More training = better recognition

10. 10 Voice Training (2) User specific Voice file Voice qualities Pronunciation Patterns of word use Preferred vocabulary

11. 11 Making Corrections Move cursor by voice command Memorize edit commands List of possible alternatives Make correction manually

12. 12 Command/Control Desktop grid Program or Link name/number URL name Memorized commands

13. 13 Recent Improvements in SR Faster training ~10 min. Better recognition ~95% More compatible software Better system control/command

14. 14 Current Software Options for PC Dragon Systems – Naturally Speaking Philips – FreeSpeech IBM – ViaVoice Lernout & Hauspie – Voice Xpress

15. 15 How well do the work? TrainingDictation Correct. App. Integrat. Command - Control DragonExcellent Good PhilipsFair Good IBMExcellentGood Excellent L & HGood

16. 16 Future of SR SUI – Speech-based User Interface Improvements needed: - Greater accuracy - Greater system control/command - More compatible software

17. 17 Conclusion SR Uses How does it work? Current Software Problems of SR More SR coming soon….

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.