Stromberg acknowledges that it's common to see bike riders with headphones in their ears, and the question about the safety of the practice is subject to debate, similar to the question of whether bikers are safer while wearing helmets or whether bikers should be able to roll through stop signs.
"The biggest problem with resolving this argument: there's no data on bikers' accident rates that compared headphone users with the rest. For what it's worth, the majority of states do not outlaw riding with headphones (although many recommend against it). Five states allow one headphone, but not both, while four others ban them entirely," explains Stromberg.
Stromberg proceeds to lay out either side of the argument and also to test out the biking-while-rocking practice, discovering that he uses his aural sense much more than he realized while on his bike.
"…if we weigh all possibilities, it's easy to see that the cost of being overcautious (not getting to enjoy music while riding) is much smaller than the penalty of being not cautious enough (getting injured or killed on a bike). In this case, erring on the side of caution makes sense."