I use a pair of soyo bluetooth headphones under my FFhelmet - they are shaped like a little rounded square on each ear and clip around each ear and they fit in the ear well of the helmet and don't cause pain. The only slight problem is if I turn them off accidentally while putting the helmet on. Then it can be a bit tricky to reach in and turn them on again. I also have another pair from another company shaped the same way and they work too but I like the soyo better. Neither pair keep out the road noise as well as in ear buds do.
This is the other type I have
http://www.newegg.com/Product/Produc...ICS-_-75984025