Earphones / Headphones: Where to try, what to buy?

But if you don't need your ears while driving, why do you need them while cycling? Especially considering you've got a 360 degree view with no blind spots which is already a massive improvement over a driver's perception. What is it about cycling that demands so much more perception than driving?

I'm sure you can cycle perfectly safe with earphones, but what i'm saying is that without headphones it's safer, and i'd rather be safer. It's that simple.