Check out SleekSpeak, a KickStarter project that will solve any audio issues you may have when riding your bike (e.g. earphone cables dangling).
SleekSpeak is a wireless speaker for your bicycle/bike. Obviously it is made especially for all you cyclists who need a safer alternative than wearing headphones while riding. It connects to your mp3 player through Bluetooth and can pump out an amazing 80 db of sound that is loud enough for your personal enjoyment, but low enough to also allow you to be aware of other sounds around you (horn, traffic etc.). Through a special silicone strap, SleekSpeak can be strapped/attached just about anywhere on your bicycle.