About a month ago I found an iPod shuffle just lying in my driveway. I asked everyone that I knew who could have possibly dropped it there if it belonged to them, but nobody was missing one. The music on it gave me no clue. I figured that it was a gift from the cycling gods.
So I loaded some tunes on it and went for a ride. I noticed pretty quickly that you could hear traffic and the music well enough below 18 mph. Riding 22 mph and up generated enough wind noise that the iPod was more of a nuisance than a pleasure.
Maybe someday I will wear it while riding again, but only on recovery ride days.