Hearing in space
When worn, the Frequency Module enables you to hear in space since the volume is extremely low without one.
To use it, simply place it in your Galacticraft inventory tab (default e).
Communicating with Alien Villagers
If you want to attempt communication with Alien Villagers - for example to do some trading - then you will need one of these!
With the Frequency Module in your main hand, left click (attack) the entity you want to track (it won't cause any damage): this picks up that entity's signal. Then walk to a Telemetry Unit and - with the same Frequency Module still in your hand - right click the Telemetry Unit. The Telemetry Unit will now track the entity.
To have a Telemetry Unit track yourself, first right click the Telemetry Unit with the Frequency Module in your hand to make the link, then wear that Frequency Module! If you stop wearing the Frequency Module, you will break the link.
There's some real science behind the Galacticraft Frequency Module! Science shows that sounds travel less far - and so will sound quieter to the listener - in the low density atmosphere of Mars.
On Space Stations, Moon, and Asteroids there is no atmosphere. But some sound can still be carried by solid structures which are touching - you will be able to "hear through your feet". So in Galacticraft, we made it so that even without the Frequency Module you can still hear some faint sounds - for example blocks breaking - in these dimensions.