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.
Assistive Listening Devices (Alds): Non-hearing aid devices used by a hearing impaired individual to improve communication and the performance of activities in specific environments. ALDs include devices such as infrared and FM personal amplifiers, alerting devices, and closed captioning equipment.