Source : Free On-Line Dictionary of Computing

Interactive Voice Response
     
         (IVR)  A {telecommunications}
        system, prevelant with {PBX} and {voice mail} systems, that
        uses a prerecorded database of voice messages to present
        options to a user, typically over telephone lines.  User input
        is retrieved via {DTMF} tone key presses.
     
        When used in conjunction with {voice mail}, for example, these
        systems typically allow users to store, retrieve, and route
        messages, as well as interact with an underlying {database}
        server which may allow for automated transactions and {data
        processing}.
     
        (15 Sept 1997)
     
        (1997-09-21)