Headphones; Earphones and headphones; Computer hardware; Noise cancelling headphones; Wireless headphones; Wearable computers in the nature of smartglasses; Wearable computers in the nature of smartwatches; Digital electronic devices and instruments containing sensors for measuring, displaying, storing, or transmitting biosignals, physical parameters, and other physiological data; Data tracking units, not for medical use, comprised of a head-worn device for measuring, tracking, and monitoring...