The Headset is one of the most important pieces of equipment you will acquire onboard SS13.
It takes the shape of a length of wire, and is used to converse with other crewmembers who are not in your immediate vicinity. the other piece of Equipment useful for this is the Station Intercom System, which requires you being in range, and turning said intercom on. There are also Station Bounced Radios which you need to hold into your hand.
You speak into your headset by adding a semicolon after the say command, like this:
say ";Can anyone hear me?
You can also make it broadcast everything you say, by taking it into your hand and enabling the speaker. Don't do this if you're having normal hallway conversations, as it can be a bit spammy.
All radio equipment is set to a frequency and will only communicate with other equipment set to that frequency.
The headset has its own Inventory slot, and there is no reason to ever remove your Headset, as nothing else fits in its slot.