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.
Long Range Acoustic Device. The LRAD is the round black device on top of the New York City police Hummer. The Long Range Acoustic Device (LRAD) is an acoustic hailing device developed by LRAD Corporation to send messages and warning tones over longer distances or at higher volume than normal loudspeakers.