1. A method of enforcing caller listening behavior on interactive voice response applications, comprising the steps of: selecting a predetermined prompt based on speech input by a caller; playing said predetermined prompt; interrupting said predetermined prompt if said caller starts to speak during playback of said predetermined prompt; determining whether the caller has spoken at least one of a plurality of predetermined reserved words or phrases; allowing full barge-in and performing a predetermined action associated with the predetermined plurality of reserved words or phrases determined to have been spoken by the caller; and playing a predetermined barge-in-acknowledgement prompt informing the caller to continue listening if it is determined that the caller has not spoken one of said plurality of reserved words or phrases and resuming playback of said predetermined prompt.