Analog measurement with gated digital trigger

I'm using the NI USB-6216 DAQ.  I need to record a sound wave when a digital "push to talk" signal goes low. The recording must stop when the PTT signal goes high (a very standard gated trigger). I see there is a digital edge trigger which can start the recording on PTT going low but I'm not sure how to stop the recording when PTT goes high.  I also see a digital change detection callback. Is that the better option (launch a measurement task on going low, kill the task on going high)?  Are there examples of both options?

Thanks in advance for your help.