There are many reasons why users need to speak and listen to mobile devices. We spend the first couple of years of our lives learning how to speak and listen to other people, so it is natural that we should be able to speak and listen to our mobile devices. As mobiles become smaller, the space available for physical keypads shrinks, making more difficult to use. Wearable devices such as Google Glass and smart watches don't have physical keypads. Speaking and listening is becoming a major means of interaction with mobile devices.

Eventually computers with microphones and speakers will be embedded into our home environment, eliminating the need for remote controls and handheld device. Speaking and listening will become the major form of communication with home appliances such as TVs, environmental controls, home security, coffee makers, ovens, and refrigerators.

When we perform tasks that require the use of our eyes and hands, we need speech technologies. Speech is the only practical way for interacting with an Android computer while driving a car or operating complex machinery. Holding and using a mobile device while driving is illegal in some places.

Siri and other intelligent agents enable mobile users to speak a search query. While these systems require sophisticated artificial intelligence and natural language techniques which are complex and time consuming to implement, they demonstrate the use of speech technologies that enable users to search for information.

Guides for "self-help" tasks requiring both hands and eyes present big opportunities for Android applications. Soon we will have electronic guides that speak and listen to help us assemble, troubleshoot, repair, fine-tune, and use equipment of all kinds. What's causing the strange sound in my car's engine? Why won't my television turn on? How do I adjust the air conditioner to cool the house? How do I fix a paper jam in my printer? Printed instructions, user guides, and manuals may be difficult to locate and difficult to read while your eyes are examining and your hands are manipulating the equipment.

Let a speech-enabled application talk you through the process, step-by-step. These self-help applications replace user documentation for almost any product.

Rather than hunting for the appropriate paperwork, just download the latest instructions simply by scanning the QR code on the product. After completing a step, simply say "next" to listen to the next instruction or "repeat" to hear the current instruction again. The self-help application can also display device schematics, illustrations, and even animations and video clips illustrating how to perform a task.

Voice messages and sounds are two of the best ways to catch a person's attention. Important alerts, notifications, and messages should be presented to the user vocally, in addition to displaying them on a screen where the user might not notice them.

These are a few of the many reasons to develop applications that speak and listen to users. This book will introduce you to building speech applications. Its examples at different levels of complexity are a good starting point for experimenting with this technology. Then for more ideas of interesting applications to implement, see the Afterword at the end of the book.

James A. Larson

Vice President and Founder of Larson Technical Services