There is a small tunnel underneath the railroad in Amsterdam where sounds similar to dripping water come from the walls. The first time I passed it I did not notice it right away, as the sounds are not very loud. But then I realized the experience of passing through that tunnel was more pleasant than usual. I love these sonic surprises and I wish I would encounter more of them throughout the city.
This Sonorous Bench created by Clint Davis, Jaime Oliver, Jacob Sudol and Chris Warren, all students at the San Diego’s music department of the University of California, is another great example of sound art in public space. Two transducers emit resonance frequencies of the bench, and make it sing. It is not too loud, just a nice, subtle addition to the urban soundscape.