Some time ago we visited the Minnesota Museum of American Art to look at the work of artists working with sound "Sound in Art Art in Sound"
http://www.mmaa.org/Sound_in_Art_Art_in_Sound.html
Margaret wrote about the exhibit here: http://ltc.smm.org/pie/node/163

I was very very interested in the work by Leif Brush, a sound artist from Minnesota who collaborating with his wife created "recordings" of the sound of frost forming on a window pane.