Join a Friends List or stand close to the player with whom you wish to chat.
One way to access the voice chat is via a Friends List. Any player added to a Friends list can automatically speak to anyone else on the same list via Voice Chat.*
Another way is to have players who are not friends move into close proximity to one another.
There are voice settings that players can adjust in a Voice Chat, such as voice input device, voice output device, voice transmission type, and volume settings.
*Please note that for a voice chat, a headset or earphone with a microphone has to be connected to the device.
Learn more by visiting the Star Atlas Discord channel.