The Long Range Acoustic Device (LRAD) is an acoustic hailing device and sonic weapon developed by LRAD Corporation to send messages, warnings, and harmful, pain inducing tones over longer distances than normal loudspeakers. LRAD systems have been used to counter piracy, as non-lethal crowd control weapons, and as communication devices.


If you wear earplug of headset might help.. I am just wondering if we have an umbrella turn the other way round and point back at the speaker. The sound wave will be deflected back toward the speaker instead. Even if it is not 100% but the effect on the resonance and vibration might help to knock off the speaker. No?