Well, I'm on the "its ok if you only have one ear covered" side. I have an iPaq with a wireless BlueTooth headset that I wear to listen to music or (egad) talk on the phone. I can say that I have never had an issue not hearing anything. In fact, the way the earpiece sits on my ear I have less wind noise with no sound coming through it. I havent been pulled over yet. I find that I ride better with music and I'm trying to put together a selection where the bpm will dictate my cadence.