 Voice-based services, especially on mobile devices, are a rapidly expanding applications area. Services range from organizers (for grocery lists, meeting schedules, reminders, contact lists, etc.), to in-car “infotainment” (routing, traffic conditions, hazard warnings, iTunes selection, finding nearby restaurants and other venues, etc.), to enabling use of other miscellaneous apps such as email dictation, dialing contacts, financial transactions, reservations and placement of orders, Wikipedia access, help-desk services, health advising, and general question answering. Some of these services (such as dialing and iTunes selection) fall into the category of hands-free controls, and such controls are becoming increasingly important in transport (including driverless or pilotless vehicles), logistics (deployment of resources), and manufacturing. Also chatbot technology and companionable dialogue agents (as discussed in  section 10.5)  are serving as general backends to more specific voice-based services.