85978736
Feb 16, 2011
Dec 3, 2013
Technological devices for improving acoustic clarity and audio transmission and reception for assisting persons with sensory or cognitive impairments and to preserve hearing levels sold as an integral component of adapted stereo headphones; cellular telephone and voice over internet protocol telephone headset units featuring technological devices for improving acoustic clarity and audio transmission and reception for assisting persons with sensory or cognitive impairments and to preserve hearing levels
Electrical and Scientific Apparatus