Noise Reduction in Speech Processing (eBook)

Preface 6
Contents 8
1 Introduction 12
1.1 Noise Reduction in Speech Processing 12
1.2 The Paradigm for Noise Reduction 17
1.3 A Brief History of Noise Reduction Research 18
1.4 Organization of the Book 21
1.5 Some Notes to the Reader 24
2 Problem Formulation 25
2.1 In the Time Domain 25
2.2 In the Frequency Domain 26
2.3 In the Karhunen-Lo`eve Expansion (KLE) Domain 28
2.4 Summary 30
3 Performance Measures 31
3.1 Signal-to-Noise Ratio 31
3.2 Noise-Reduction Factor 34
3.3 Speech-Distortion Index 35
3.4 Speech-Reduction Factor 37
3.5 Discussion 38
4 Mean-Squared Error Criterion 40
4.1 In the Time Domain 40
4.2 In the Frequency Domain 41
4.3 In the KLE Domain 43
4.4 Summary 45
5 Pearson Correlation Coefficient 46
5.1 Correlation Coefficient Between Two Random Variables 46
5.2 Correlation Coefficient Between Two Random Vectors 47
5.3 Frequency-Domain Versions 48
5.4 KLE-Domain Versions 48
5.5 Summary 49
6 Fundamental Properties 50
6.1 In the Time Domain 50
6.2 In the Frequency Domain 55
6.3 In the KLE Domain 59
6.4 Summary 66
7 Optimal Filters in the Time Domain 67
7.1 Wiener Filter 67
7.2 Tradeoff Filters 72
7.3 Subspace Approach 75
7.4 Experiments 76
7.5 Summary 83
8 Optimal Filters in the Frequency Domain 85
8.1 Wiener Filter 85
8.2 Parametric Wiener Filter 89
8.3 Tradeoff Filter 90
8.4 Experiments 94
8.5 Summary 102
9 Optimal Filters in the KLE Domain 103
9.1 Class I 103
9.2 Class II 113
9.3 Experiments 119
9.4 Summary 129
10 Optimal Filters in the Transform Domain 130
10.1 Generalization of the KLE 130
10.2 Performance Measures 134
10.3 MSE Criterion 138
10.4 PCC and Fundamental Properties 139
10.5 Examples of Filter Design 145
10.6 Experiments 153
10.7 Summary 159
11 Spectral Enhancement Methods 160
11.1 Problem Formulation 160
11.2 Performance Measures 162
11.3 MSE Criterion 166
11.4 Signal Model 168
11.5 Signal Estimation 169
11.6 Spectral Variance Model 173
11.7 Spectral Variance Estimation 177
11.8 Summary of Spectral Enhancement Algorithm 181
11.9 Experimental Results 183
11.10 Summary 188
12 A Practical Example: Multichannel Noise Reduction for Voice Communication in Spacesuits 190
12.1 Problem Description 190
12.2 Problem Analysis 193
12.3 Suggested Algorithms 199
12.4 Algorithm Validation 210
12.5 Summary 224
Acknowledgments 225
References 226
Index 234