Hello, I found this is a question that was asked before by others, but I didn't find the answer. Anyway, I am using FS ESL outbound mode connecting to my IVR app, using FS's "speak" and "detect_speech" to access Nuance MRCP V1 server. I want the user to be able to barge-in during the system's speaking. How could I implement it? I tried to specify "kill-on-barge-in=true" in the mrcp config profile. The barge-in doesn't work. With or without setting kill-on-barge-in, FS stops responding to my phone call and eventually it hangs up my call if I speak somthing (do the barge-in) during the system's speaking. I made a turn-by-turn loop in my app, the ASR/TTS works fine if I do not do barge-in ( I wait until the TTS finishes then I start to speak) Any advices please? Thanks! Xing -- Heriot-Watt University is a Scottish charity registered under charity number SC000278. Heriot-Watt University is the Sunday Times Scottish University of the Year 2011-2012