Automatic Number Identifier is the number the caller is calling from. Consider the number that shows up on the caller ID - that's the caller's ANI. ANI is useful in the IVR setting as it allows the system to identify (at least partially) the caller. The idea is to perform an ANI lookup, and if a match is found, ask the caller for a subset of information for authentication purposes.


The capacity of a system to allow the user to interrupt the prompt that is playing by speaking over it. All systems allow the developer to turn barge-in on or off. The DTMF equivalent term is "key-over" and refers to the capability to interrupt a prompt by pressing a key.


Dialed Number Identification Service tells the IVR which number the caller dialed. DNIS's are typically 4 to 10 digits in length and most of the time can be mapped to a toll-free number. DNIS is often used to intelligently route calls in which multiple TFNs (or DNIS's) come into one application. DNIS-based routing allows the system to play specific welcome messages, main menus, etc. and even facilitates transferring the caller to the appropriate agent group if necessary.


A short sound used to communicate an event or a convey a landmark during a voice interaction. Examples of earcons include:
  • A short tone at the main menu to indicate that the caller is at that particular place in the interaction.
  • The sound of a door closing during a conference call to indicate that a participant has left the bridge.

Note that an earcon is typically meant to convey information. If the sound is just being used for marketing or branding purposes, the better term would be "sonic branding" or something similar.


Refers to a communication structure in which two parties (the IVR and the caller) take turns speaking. The IVR asks a question or presents a menu, and pauses, alerting the caller that it is her turn to speak. The caller in turns responds, and so the turn-taking continues.