Speech technology in telecommunications

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Code Completion Credits Range Language
A2M31RAT Z,ZK 6 2+2c Czech
Department of Circuit Theory

The subject is devoted to basis of speech processing addressed to students of master program with special focus on communication applications as speech technology has currently many applications in communication systems. Further information can be found at http://noel.feld.cvut.cz/vyu/a2m31rat . Detailed information for registered students can be found at teaching portal http://moodle.kme.feld.cvut.cz .


Bases of digital signal processing are supposed as preliminary knowledge.

Syllabus of lectures:

1. Introduction - speech signal, basic characteristics, speech production model

2. Digitalization and basic coding strategies (PCM, ADPCM, a-law)

3. Spectral characteristics of speech signal (DFT a LPC spectrum, LSF a LSP)

4. Vocoders used in telecommunications (RPE-LTP, CELP, ACELP)

5. Methods of noise suppression for speech signals (channel and acoustic noises, VAD)

6. Echo cancellation in speech signal

7. Measurement of speech quality (subjective and objective methods)

8. Principles of speech recognition: basic tasks, feature extraction, DTW algorithm

9. Small vocabulary recognizer based on HMM (HTK toolkit)

10. Speaker recognition: verification and identification.

11. Speech synthesis - basic principles (concatenative and formant synthesis, PSOLA)

12. Voice controlled dialogue communication systems

13. Packet loss concealment for speech transmitted via communication channel

14. Further application of speech processing in communication systems. Reserve

Syllabus of tutorials:

1. Introduction: speech signal, tools for analysis, sources of speech signals

2. Basic time-domain characteristics: energy, intensity, zero-crossing, fundamental frequency

3. Spectral characteristics: short-time DFT and LPC spectrum, spectrogram

4. LPC based vocoder: implementation of particular functional blacks

5. Suppression of additive noise in speech signal

6. Echo cancellation

7. Cepstrum and cepstral distance: voice activity detection, features for recognition

8. DTW based recognition: simple recognizer of particular words

9. HMM based recognition: basic tasks and demonstration of HMM modelling

10. Speaker verification based on GMM

11. Speech synthesis: implementation of formant synthesis, demonstration of available tools

12. Semester work presentations

13. Semester work presentations

14. Reserve. Credits

Study Objective:

The goals of the subject is to introduce used speech technology in the most important communication applications. Students should manage the knowledge as basic characteristics of speech signal, speech coding, speech enhancement, speech recognition, speech synthesis, etc. Students will practice basic tasks of speech processing in MATLAB environment and also other publicly available tools for speech analysis will be used. As a homework, students will elaborate semester project which will be presented at the exercise according to planned schedule.

Study materials:

[1] Huang, X. - Acero, A. - Hon, H.-W.: Spoken Language Processing. Prentice Hall 2001.

Further information:
No time-table has been prepared for this course
The course is a part of the following study plans:
Data valid to 2019-08-18
For updated information see http://bilakniha.cvut.cz/en/predmet12525904.html