About voice applications

A voice application provides a Voice User Interface (VUI) that permits telephone callers to interact with a computer system simply by listening and speaking. It automates conversational exchanges between a caller and the system—collecting information that the system needs to perform a task, such as getting an account number or finding out the name of the person the caller wants to speak with.

A voice application consists of one or more text files written in VoiceXML, a standardized extensible markup language that has been designed specifically for this purpose. Each VoiceXML file describes a dialog—a conversation the application has with the caller.

The VoiceXML files in an application are read and interpreted by a VoiceXML browser. This VoiceXML browser concatenates and plays prompts, invokes audio files, executes scripts, performs error-recovery and logging, determines how the caller’s responses are interpreted, provides that interpretation to the computer system, and reacts to the computer system’s responses.

A VoiceXML file may refer to other types of files which must also be created to support the application. These include audio files to be played to the caller, and grammar files that define the words and phrases that the application understands when a caller says them.