Crickets

Space is muffled.  Up there is really out there, and out there is very little stuff.  I mean, everything else in the universe is out there, but it's very spread out.  Sound needs a more dense medium.

Other waves of energy, however, don't. Our ears are tuned to low energy waves.  It's the energy our bodies are capable of expending to create them.

Imagine being a creature out there capable of hearing the higher energy waves... listening, hearing all of the waves we've just relatively recently been able to make.  Would that make it curious?  Or, would it just want to crush us like a noisy cricket?