Barge-in

"Barge-in is a feature that allows callers to interrupt a prompt and provide their response before the prompt has finished playing" at pag. 24 of book "Voice User Interface Design" by James Giangola et al.

In other words, barge-in is, in any voice interface system / voice assistant, the user capability of interrupt/stop the assistant spoken (a text-to-speech synthetic voice play), to impose a new overriding user voice request to be processed asap.