1 a wasting away of the body, as from poor nutrition, nerve damage, or disuse. 2  to undergo atrophy; wither; degenerate:His crippled leg began to atrophy with no exercise. 3  to become weakened; decline:Industry atrophied in bad economic times.
Voice Amplifiers / Long Range Listening Devices. Listening devices can be utilized for a variety of purposes including listening through a wall, listening from a distance or enjoying your favorite animals in the wild. More complex systems contain an audio transmitter and receiver.
The term Assistive Listening Systems (ALS) is a generic description of several different technologies that essentially do the same thing: they are used to improve the reception of speech for people with hearing loss in situations when it might be difficult or impossible to hear otherwise.