1. The Application of Hidden Markov Models in Speech Recognition
Author：Mark Gales1 and Steve Young2
Published：21 Feb 2008
Subjects：Speech/audio/image/video compression

2. Outline Introduction Architecture of an HMM-Based Recogniser
HMM Structure Refinements
references

3. CHAPTER 1: Introduction

4. There is no data like more data. Recognition word error rate vs
There is no data like more data. Recognition word error rate vs. the amount of training hours for illustrative purposes only. This figure illustrates how modern speech recognition systems can benefit from increased training data.

5. Automatic continuous speech recognition (CSR) has many potential applications including command and control, dictation, transcription of recorded speech, searching audio documents and interactive spoken dialogues.
in the last decade or more, the detailed modelling techniques developed within this framework have evolved to a state of considerable sophistication.
Since speech has temporal structure and can be encoded as a sequence of spectral vectors spanning the audio frequency range, the hidden Markov model (HMM) provides a natural framework for constructing such models [13].

6. CHAPTER 2: Architecture of an HMM-Based Recogniser

7. Architecture of a HMM-based Recogniser
Bayes’ Rule
Acoustic
Models
Language
Model
Acoustic
Models
Language
Model

8. HMM-based phone model
HMM Acoustic Models

9. Formation of tied-state phone models
Fig. 2.4 Formation of tied-state phone models.

10. N-gram Language Models

11. CHAPTER 3: HMM Structure Refinements

12. Dynamic Bayesian Networks
In Architecture of an HMM-Based Recogniser, the HMM was describedas a generative model which for a typical phone has three emitting

13. Gaussian Mixture Models

14. Covariance Modelling Structured Covariance Matrices
Structured Precision Matrices

15. references
使用中
The Application of Hidden Markov Modelsin Speech Recognition
A Historical Perspective of Speech Recognition
Automatic Speech Recognition – A Brief History of the Technology Development
Bayesian Networks