So, what i do is when receiving a clearance. i read back and end with my callsign. eg. CENTER SAYS "DAL 1207, climb maintain 5000, turn left to heading 350 deg". I respond... CLICK "Roger, Climb maintain 5000, turn right 350 DAL 1207"....UNCLICK. As soon as i unclick., Center is calling UAL 2345, climb ......DAH DAH DAH that tells me he heard and understands....If i wait 3 seconds after i announce my callsign to release the transmit button.... I will be gettin some angry eyes from the approach controller.