Preface

The idea of being able to talk with a computer has fascinated many people for a long time. However, until recently, this has seemed to be the stuff of science fiction. Now things have changed so that people who own a smartphone or tablet can perform many tasks on their device using voice—you can send a text message, update your calendar, set an alarm, and ask the sorts of queries that you would previously have typed into your search box. Often voice input is more convenient, especially on small devices where physical limitations make typing and tapping more difficult.

This book provides a practical guide to the development of voice apps for Android devices, using the Google Speech APIs for text-to-speech (TTS) and automated speech recognition (ASR) as well as other open source software. Although there are many books that cover Android programming in general, there is no single source that deals comprehensively with the development of voice-based applications for Android.

Developing for a voice user interface shares many of the characteristics of developing for more traditional interfaces, but there are also ways in which voice application development has its own specific requirements and it is important that developers coming to this area are aware of common pitfalls and difficulties. This book provides some introductory material to cover those aspects that may not be familiar to professionals from a mainstream computing background. It then goes on to show in detail how to put together complete apps, beginning with simple programs and progressing to more sophisticated applications. By building on the examples in the book and experimenting with the techniques described, you will be able to bring the power of voice to your Android apps, making them smarter and more intuitive, and boosting your users' mobile experience.