While out all alone in the blackness of
Voyager 1's plasma wave instrument detected the vibrations of dense interstellar plasma, or ionized gas, from October to November 2012 and April to May 2013.
The graphic shows the frequency of the waves, which indicate the density of the plasma. Colors indicate the intensity of the waves, or how "loud" they are. Red indicates the loudest waves and blue indicates the weakest.
It has already send back recordings of what that empty blackness of space 12 billion miles from the sun sounds like. And it's quite creepy. Listen: