We stopped by KDDI's booth at CES and got some hands-on time with a prototype Kyocera "Speaker-less Smartphone." Instead of using a speaker, the device vibrates inaudibly, but when you press any part of the screen against your ear the vibrations get sent up your ear canal so you can hear what's playing. There are a lot of advantages to the technology — it allows you to hear clearly in noisy environments, while wearing ear mufflers, or even while listening to music on headphones — and battery consumption is said to be lower than conventional speakers. KDDI wasn't announcing any plans to ship the device in the US, but the rep on site told us that it should be on the Japanese market sometime in 2012.