re: Question
You need a physical medium for sound to travel "in"- like air or water- until it reaches your ear.
It takes energy to put air molecules in motion- create sound.
If there is no medium to transmit the energy of the 'source' (lets say someone hitting the robotic are in the space shuttle bay with a hammer) then the source will experience an increase in temperature slightly higher than normal. ( Normally, when objects collide, heat is created and is equal to the loss of momentum of the objects)
Both the arm and the hammer will be warmer by the amount of energy that would usually be carried away in the form of sound.
The vacuum of space acts like an insulator...
I think
:)