Table of Contents
Acknowledgments v
Introduction 1
1 Overview of speech and language technologies Deborah Dahl 7
1.1 Introduction to speech and language technologies 7
1.2 Speech recognition 11
1.2.1 What is speech recognition? 11
1.2.2 Additional information confidence and nbest 13
1.2.3 Types of language models 14
1.2.3.1 Grammar-based language models 14
1.2.3.2 Statistical language models 15
1.2.4 When can speech recognition help? 16
1.2.5 Limits of current technology 17
1.2.6 Availability of speech recognition technology 18
1.3 Natural language understanding 19
1.3.1 What is natural language understanding? 19
1.3.2 Analyzing meaning 19
1.3.3 Information about intermediate structure 24
1.3.4 Converting language to action 25
1.3.5 Limits of current natural language understanding systems 26
1.3.6 Availability of natural-language-processing technology 26
1.4 Dialog systems 27
1.4.1 What are dialog systems? 27
1.4.2 When can dialog systems help? 30
1.4.3 Limitations of current systems 32
1.4.4 Availability of dialog system technologies 33
1.5 Text-to-speech 33
1.5.1 What is TTS? 33
1.5.2 Where could it help? 34
1.5.3 Limits of current systems 34
1.5.4 Availability of TTS systems 36
1.6 Natural language generation 37
1.6.1 What is natural language generation? 37
1.6.2 Where could natural language generation help? 37
1.7 Text simplification 38
1.7.1 What is text simplification? 38
1.7.2 Where could text simplification help? 38
1.7.3 Limits of current systems 38
1.8 Complementary technologies 39
1.9 Conclusions 40
References 40
2 Overview of developmental language disorders Katharine Beals 43
References 47
3 Technology for assessment and remediation of developmental language disorders Katharine Beals 51
3.1 Linguistic technologies for assessing language needs 51
3.2 Linguistic technologies for remediation 58
3.2.1 Programs that address phonological processing 68
3.2.2 Programs that address comprehension, or receptive language 69
3.2.3 Programs that address productive language 84
References 101
4 Technology for task assessment, classroom accommodation, and communicative assistance of developmental language disorders Katharine Beals 105
4.1 Linguistic technologies for task assessment reading tasks in particular 105
4.2 Linguistic technologies for classroom accommodation 108
4.3 Assistive communication technologies for developmental language disorders 110
References 118
5 Conclusions and caveats about developmental language technology Katharine Beals 119
References 124
6 Overview of acquired aphasia and disorders of word retrieval Ruth Fink 125
6.1 Aphasia 125
6.1.1 Fluent aphasia 125
6.1.2 Non-fluent aphasia 126
6.1.3 Living with aphasia 126
6.2 Disorders of word retrieval in aphasia: "I know it but I cannot say it" 127
6.3 Approaches to treating word production disorders in aphasia 130
6.3.1 Lexical-semantic treatments 130
6.3.2 Lexical-phonological treatments 131
6.3.3 Semantic and phonological tasks are rarely pure 131
References 132
7 Software for aphasia: computer-assisted treatment of word retrieval deficits in aphasia Ruth Fink 135
7.1 Technology foraphasia: what are the benefits? 135
7.2 Language software for aphasia: what is the evidence? 135
References 138
8 Software for aphasia: MossTalk Words® (MTW) Ruth Finkand Deborah Dahi 141
8.1 About MossTalk Words: a computer-implemented treatment 141
8.2 Research on MTW 144
8.3 Speech recognition in MTW-2 145
8.4 Conclusions 148
8.5 Commercial programs using speech recognition for word retrieval deficits in aphasia 149
8.6 The challenge 149
8.7 Moving beyond words 149
8.7.1 Speech-to-text/text-to-speech software 150
8.7.2 Role of the speech-language pathologist 151
References 152
9 Speech technology for aphasic sentence production disorders Marcia Linebarger 155
9.1 Background: language production in non-fluent aphasia 155
9.1.1 Explanations 156
9.1.1.1 Pathologically reduced short-term/working memory or resource diminution 156
9.1.1.2 Weak activation of linguistic elements 157
9.1.1.3 Difficulty with "thinking for speaking" 157
9.1.2 Approaches to treating sentence production in non-fluent aphasia 158
9.1.2.1 Drill/practice exercises to increase activation of particular items or structures 159
9.1.2.2 Treatments to improve thinking for speaking 159
9.2 Scope of the term "speech technology" 161
9.3 A tale of two programs 161
9.3.1 The "TS": using speech technology for sentence production drills 161
9.3.2 SentenceShaper: enlarging the buffer for language 164
9.3.2.1 How the program works 165
9.3.2.2 A note about "lexical bootstrapping" 172
9.3.2.3 SentenceShaper's "aided effects": theoretical implications 173
9.3.2.4 Impact of narrative-based therapy with SentenceShaper 174
9.3.2.5 Using SentenceShaper to train specific structures 177
9.3.3 Interleaving drill with narrative production: TS and SentenceShaper together 178
9.3.4 SentenceShaper research: some bottom lines 179
9.3.5 Future directions: using SentenceShaper to enhance life participation 180
9.4 Survey of speech technology for sentence production 181
9.4.1 Software that analyzes the user's speech 181
9.4.1.1 Goal: To give feedback about correctness and completeness 182
9.4.1.2 Goal: To enable the user to engage in complex tasks 184
9.4.1.3 Goal: To create a text transcript 185
9.4.1.4 Goal: To analyze speech patterns for diagnostic purposes 186
9.4.2 Software that records and plays back the user's speech 186
9.4.2.1 Goal: To allow users to edit their speech 186
9.4.2.2 Goal: To let users compare their speech to a model 187
9.4.2.3 Goal: To enhance communication 187
9.4.3 Software that transmits the user's speech 188
9.4.4 Helpful software not covered in this chapter 189
9.4.4.1 Iconic communication aids 189
9.4.4.2 Software for script training 189
9.4.4.3 Speech recognition to support comprehension 189
9.4.4.4 Software to track speech activity 190
9.5 Summary 190
References 191
10 Evaluating speech and language applications for language disorders Deborah Dahl 195
10.1 Use of the software 195
10.1.1 Some general considerations 195
10.1.2 Efficacy 196
10.1.3 Time to results (for remediation software) 197
10.1.4 Learning to use the software 197
10.1.5 User engagement 197
10.1.6 Responsiveness/robustness/implementation quality 198
10.1.7 Feedback 198
10.1.8 Accuracy of speech and language technologies 198
10.1.9 Usability in light of other issues 199
10.2 Contextual and support features 199
10.2.1 Cost, including initial cost and updates/new materials 199
10.2.2 Multiple users 199
10.2.3 Personalization and customization 199
10.2.4 Support/user community/documentation 200
10.2.5 Languages 200
10.2.6 Extensibility and growth 200
10.2.7 Record keeping 201
10.2.8 Assessment 201
10.2.9 Administration-201
10.2.10 Platform is the product available on convenient, widely available platforms? 201
10.2.11 Evaluation strategy 202
11 Conclusions 203
11.1 Feedback 203
11.2 Assistive and remediative goals 203
11.3 Acquisition and repair 204
11.4 Reinforcements/rewards 204
11.5 Next steps 204
Authors' biographies 207
Index 211
