Lock me up. I wear them on occasion and usually don't have the volume so loud as to obscure outside sounds. I can still hear better than I can in a car with all it's sound damping and with the radio going, and I certainly can hear much better than on my motorcycle. And although hearing can be helpful, my first line of defense in situational awareness aided by wearing and using a mirror.

And how is this inviting to get hit by a car? You might argue that riding in dark clothing and not using lights at dusk is inviting to get hit because it affects the driver's ability to see you. But riding with headphones, or while deaf for that matter, has no effect on a driver's ability to see and avoid you.