1. Speaker Recognition
By Afshan Hina

2. Overview What is speaker recognition? Voice Pattern
Categories of Speaker recognition.
Verification versus identification
Phases of speaker recognition
Technology used
Advantages and disadvantages
Conclusion
Commentary

3. Speaker Recognition
Also referred as voiceprint recognition or voice recognition.
Identifies sound.
Such systems extract features from speech, model them and use them to recognize the person from his/her voice.
Differs from speech recognition- where words are identified and not speaker.
r  eh k ao g n ay  z       s  p  iy  ch
"recognize speech"
r  eh  k     ay     n  ay s     b  iy  ch”
"wreck a nice beach"

4. Voice patterns
uses the acoustic features of speech that have been found to differ between individuals.
These acoustic patterns reflect both anatomy and learned behavioral patterns

5. Voice patterns
But the data used in a voiceprint is a sound spectrogram, not a wave form.
Spectrograms also use colors or shades of grey to represent the acoustical qualities of sound.

6. Categories
Field text
Text dependant
Text independent
Conversational.

7. Verification versus identification
Speaker verification: If the speaker claims to be of a certain identity and the voice is used to verify this claim. Is usually used in applications which require secure access. Its a 1:1 match.
Speaker identification: is the task of determining an unknown speaker's identity. It’s a 1:N match

8. Phases of speaker recognition
Enrollment Phase: During enrollment the speaker's voice is recorded and typically a number of features are derived to form a voice print, template, or model.
Test Phase: In the test phase (also called verification or identification phase) the speaker's voice is matched to the templates or models

10. Technologies used: frequency estimation hidden Markov models
pattern matching algorithms
neural networks
matrix representation
decision trees

11. Advantages Remote authentication over legacy phone line.
Users do not have to remember passwords or pass phrases.
Users do not have to go through separate process of verification.

12. Disadvantages Misspoken or misread prompted phrases.
Extreme emotional states
Time varying microphone placement.
Poor or inconsistent room acoustics
Channel mismatch
Sickness
Aging.

13. Conclusion
speaker verification is a pervasive low cost way of including a biometric check.
does not require specialized equipment to use the system.
It provides a very strong binding between the presented credential (voice) and the user.

14. Commentary
Although speaker verification performance can be affected by various human and external factors, it does provide a powerful authentication solution.