The stations have only a few controls. There's a mute switch that controls your microphone, it only has two options; off and on. There's a (yellow) volume control for how loud you can hear the intercom audio. There's a (green) volume control for how loud you can hear the audio monitor (which may be the program sound for your production).
Set your volume controls to suit yourself. Your microphone sends out at a fixed level (when it's switched on), you can't adjust its level.
The microphone mute switch should be used to silence the microphone when leaving headsets unattended, when you need to have a private conversation with someone near to you, or need to avoid disrupting everyone else on the intercom system.
Some directors prefer you to leave your mike switched off, and only turn it on when replying to questions, to keep the intercom system quiet. I prefer mikes to be always on, so you can reply instantly, and not have to take your hands away from operating the equipment to mess with the intercom. Find out what the director wants before starting a production.
You didn't pay for it, so it's not yours to abuse. And hiring it doesn't give you license to damage it. The beyerdynamic headsets are horrendously expensive, so if you don't want to shell out hundreds of dollars to replace damaged ones, look after them.
Switch off your microphone when leaving stations unattended. Any noise picked up by its microphone will be heard by all other stations. This can be very disruptive to operations.
Do not drop headsets onto desks, crash them to the ground, bang them on tripods, etc. Everyone else gets to hear the racket you create when you knock headsets, and it's bloody annoying.
The headphones are not completely isolated. If the volume is loud enough, the talkback audio can be heard outside of the headphones. This means you need to keep a safe distance from any recording microphones.
When you're not wearing the headset, it can feed back into itself, as your ears are not sealing the earpads, and the microphone is only a few inches from them. Switch off the mike before taking headsets off.
Even when wearing the headsets, feedback can still occur, as sound gets mechanically transmitted through its bodywork. This shouldn't normally happen, with our headsets, as the volume can't usually be turned up that much. Turn the volume down if it happens.
If using a loudspeaker station, then other headphone stations need to be kept away from it, else the speaker can feed back into them. Although some stations have a null control, it only nulls out their own microphone.
This is a party-line system, everyone is connected together as one group. This means that everyone knows what everyone else is up to. This helps to co-ordinate a small production.
For specialised jobs, a different intercom system may be used, where some stations are able to be isolated from the group.
This could be an IFB (interruptable fold-back) system, where an earpiece is supplied to an announcer that usually carries the program audio, but can be interrupted by the director to give them instructions.
It could be a multigroup system, where the director speaks to everybody. And, at the same time, some groups work in a semi-isolated state, such as: Cameramen and their CCU operators can talk to each other all the time, hear the director's instructions, without the director hearing their chatter, but can talk back to the director when they flick a switch. The audio crew may operate similarly, with the boom operator and sound mixer freely able to talk to each other, without interrupting the director, but able to hear the director. And the lighting department may have their own group, operating in a similar way.