lrad

noun

1. (abbreviation, alt-of, initialism)Initialism of long-range acoustic device: an acoustic hailing device used to send messages and warning tones over longer distances or at higher volume than normal loudspeakers.

   “Since the early 1990s, long-range acoustic devices – also known as LRADs – have helped authorities control crowds of people, especially protesters. They emit a loud, painful sound over a long distance and make people run away.”

   ““The energy may be acoustic, pressure waves, you’ve probably heard of LRAD devices (or long-range acoustic devices) – devices they’ve discussed in the press – so ultrasound is one mode that could be used for this. We also could have radiofrequency.”