^ I agree with @
_ForceD_'s sentiment completely. I prefer to hear the sounds around me.
Safety isn't the only consideration. The larger question is why folks need something playing into their heads in order to ride a bike...
Conversely, I see professional athletes (not hockey players, fortunately), who have personal music piped into their brains while they warm up. This may be to drown out distractions, pump up adrenaline, or permit relaxation leading to focus. It's not unusual for professional disc golfers to have headphone music during competitive rounds, and I'm guessing it's for one of the above reasons.
If a loved one asked me for advice, I'd recommend not doing it. If an internet stranger were to ask me, I'd say do whatever you want to do. If you're killed as a result, so be it.