This might be a bit far fetched, but what the hey...
Thrusting is actually one of the things that could be heard in a spacesuit, provided it is hit by the gasses ejected by the thrust. The pitter-patter of millions of small molecules, hehe. Of course, this would only be the case if you were fairly close to the engine, since the pressure should drop at the cube of the distance even with a constant burn rate.
Likewise, if you are in a spacesuit attached (via magnetic shoes for example) to a vehicle, and that vehicle performs a burn, you are likely to pick up the sound through vibrations in the hull. It won't sound the same as what's heard inside, but there will be some kind of sound.
I haven't studied the scenes to find the sound effects in question, but it just
might be something they thought of
