While not required, it is recommended that you enable voice chat. Alternatively, you can use the textchat if you are not comfortable using voice chat.
Voice chat works on a AOE (Area of effect) basis. This means that it is based on range. The closer you are to a player, the more likely you are to hear them, and vice-versa.
By default, voice chat should be set as 'N' to talk. You can change this by pressing ESC > Settings > Voice Chat. We recommend not using push to talk as it can be difficult to try and press a button while you're in the middle of action! Voice activated is most recommended.