Ok I gotta ask: What's the trigger for?

Radio and intercom: On the cyclic there is likely a trigger (think Top Gun, "too close for missiles, switching to guns."). Different helicopters work different ways. Sometimes you pull the trigger half-way to use the intercom, and all the way to talk on the radio. Other times you push up for intercom, and squeeze the trigger for radio broadcast. There is also, usually, a floor switch that looks like the old-fashioned high-beam floor switch in a car. This will also work either the intercom or radio. If you have time and the aircraft is under control, play around with these and see if you can talk to someone.