A Tree Ring Turntable
Bartholomäus Traubeck’s turntable captures the rings of a tree with a camera on the end of the tone arm, and converts the images into sounds.
The result: the sound of roundnesses grown year on year.
More round sounds, this time from the rings of a tree
See also an interview with the creator, and articles on core77.com and AIAIAI.dk about the piece, which he calls Years.