What are voice applications? Voice applications are applications in which the input and/or output are through a spoken, rather than a graphical, user interface. The application files can reside on the local system, an intranet, or the Internet. Users can access the deployed applications anytime, anywhere, from any telephone.
Why create voice applications? Until recently, the World Wide Web has relied exclusively on visual interfaces to deliver information and services to users via computers equipped with a monitor, keyboard, and pointing device. In doing so, a huge potential customer base has been ignored: people who (due to time, location, and/or cost constraints) do not have access to a computer.
What is VoiceXML? The Voice eXtensible Markup Language (VoiceXML) is an XML-based markup language for creating distributed voice applications, much as HTML is a markup language for creating distributed visual applications. It is an industry standard defined by the World Wide Web Consortium (W3C) at http://www.w3.org/TR/voicexml21/ (for VoiceXML V2.1) and http://www.w3.org/TR/voicexml20/ (for VoiceXML V2.0).
What are the advantages of VoiceXML? While you could certainly build voice applications without using a voice markup language and a speech browser (for example, by writing your applications directly to a speech API), using VoiceXML and a VoiceXML browser provide several important capabilities:
How do users access the deployed application? When your voice applications are deployed, users simply dial the telephone number that you provide and are connected to the corresponding voice application. The figure below shows a flow chart of a typical call.