I can't hear you. I've got a banana in my spacesuit.
Basic Information
Sound comes to you in the form of vibrating air molecules. And what does outer space lack?
(Air is the answer I'm looking for, but "a really good café mocha" would also technically be accurate).
Yet, despite this fact, Sci Fi films constantly feature sound - roaring explosions, whining engines, "Pew Pew Pew"-ing lasers, the song of the spacewhale, and other silly things that make no sense.
There's various reasons involving artistry and the established standards of the medium. See Translation Convention, Rule of Perception and Coconut Effect if you're really interested.
If you'd rather know how it really works, see In Space No One Can Hear You Roll The Dice.
Sources
Game and Story Use
- Movies break the laws of physics because otherwise extended fight sequences in silence might be boring. In gaming, you're describing everything, anyway, so being realistic doesn't cost you viewers. The choice then becomes one of verisimilitude (and logic) vs familiarity (and a little bit of the Rule Of Cool).
- Common justifications:
- The "noise" is actually generated by computers to present sensor data from outside a user's visual field. Especially useful in Old School Dogfighting, where pilots/gunners/etc are either looking out a window or using some sort of VR.
- You're using a version of space that isn't vacuum. Hyperspace or subspace might be filled with some kind of transmission medium, or maybe your ships are in the Luminiferous Ether.