In order to hear every word of a mobile phone conversation that takes place in a crowd, some people will go to the extreme of using “bone conduction” devices. This kind of device will transmit sound through the bones, such as the jawbones, rather than the eardrums. As long as you get used to the idea and the rather hollow sounds, you might find this technology a good idea.

So far popular in several countries, including Japan, which is home to some of the world’s most crowded places. The folks at DoCoMo have come out with a hands-free kit using this bone conduction technology, so you can have your conversation without having to hold onto the phone. Especially if you’re in a crowded, noisy place, you’ll appreciate not having to worry about someone bumping your arm and making you drop your phone.