n. A small computer or electronic device designed to be worn in the ear.
2015
And finally, getting back to the ear, LeBoeuf said we may someday soon have "hearables": in-ear devices that provide private, intelligent communication along with super-accurate biometric measurements.
2014
Smart ear devices, or "hearables," are the new horizon in the wearable space and for good reason. Current wearables — fitness wristbands, heart rate straps, even Google Glass — tend to be novelty-based and require convincing consumers to put something new on their body. Alternatively, ear devices have the potential to make a lasting impact in the wearable space.
2014
Here, in the hyperconnected world of wearable technology, such as Google Glass or Fitbit watches, enter hearables, a small device you wear in your ear. If one forecaster watching this market closely is correct, hearables are about to hit the market in a big way.
2014 (earliest)
I think they’ve all missed the largest potential market for wearables — a category I’m going to call Hearables. The ear is the new wrist.
See also Kerry Maxwell's excellent piece on the word hearable over at Macmillan Dictionaries.