Barge-in is what happens when the customer cuts in on the agent, interrupts the response, contradicts a confirmation, asks a different question mid-explanation. In a human conversation this is constant; in voice AI it is the difference between feeling natural and feeling like a recorded prompt.
Production-grade barge-in handling does three things. It detects the new audio quickly (sub-200 ms after the caller starts). It stops the TTS stream mid-syllable, not at the next sentence boundary. And it discards the partial response the agent was going to give and starts fresh, without losing the conversation context.
Cheap barge-in skips the third step: the agent stops talking but still completes its old thought in the next reply. Customers find this uncanny, the agent answered the question they didn't quite ask.
Vorel barge-in cuts the TTS stream within 180 ms and clears the in-flight response. The next reply is fully responsive to what the caller actually said.