How does the caller interact with the VoiceXML application?

In the example, a list of options is played to the caller and the caller is asked to make a selection by pressing a key on the telephone keypad (a DTMF key). Keys can also be used to enter identification numbers and so on.

As an alternative to pressing keys, VoiceXML dialogs can allow callers to respond by speech. The speech can be either recognized or recorded. To record the caller’s speech and and store it as an audio file on the Web server, the Web server must support HTTP POST, which allows data to be sent to an originating Web server.

For more information about speech recognition see Speech Recognition.