Aftershokz says the headphones produce high, stereo quality sound, directly through the skull to the inner ear," but why would you want to wear headphone on your cheeks? If you're someone who sports headphones on a daily basis, then you're potentially damaging your eardrums over time by putting them that close to a source of sound. For those who use phones while running, biking or doing other things outside - wearing headphones prevents you from being able to hear what's going on around you. While it might be nice to block out the outside world, it's also unsafe and could ultimately lead to an injury.