I was about to comment on the same thing. Please do not wear headphones. The consequences are major harm from an accident with much larger vehicle is great. Not worth it.

For music, I use an open-mesh-top stem bag and an all-in-one-mp3-player-speaker or just my smartphone. I can barely hear when biking fast (I commute with a road bike and haul ass), but it's just perfect for big climbs when you need a bit more motivation.

Here is what I use: http://www.ebay.com/itm/New-and-Useful-Bike-Bicycle-Cycling-...