In relation to the post above, here is a demonstration of advanced sympathetic vibration. Sound travels through the air (the A E T H E R) similar to light and when it contacts another object, the object in question vibrates (attempts to mimic what it hears). It is especially noticeable when the receiving object hears its own fundamental frequency (or it's multiples/harmonics).

In the case of this video, the dude screams, which acts similarly to white noise the more distorted the scream is. White noise is essentially all frequencies played at the same time. Theoretically, the strings (assumed to be tuned chromatically) should vibrate sympathetically much more equally as a result. However, there is still a two-note phrase present which is comprised of the lesser audible fundamental frequencies, G4 down to F4 (whole step). I could not make out a prominent pitch from the strings' sympathetic vibrations from the video. However, if we were there and listened closely, we'd hear G and F along with their multiples.