https://www.vice.com/en_us/article/dyzpna/audio-engineers-built-a-shield-to-deflect-police-sound-cannons

Over the past two weeks, cops have been deploying every tool at their disposal to suppress worldwide protests and riots over the deaths of George Floyd, Breonna Taylor, Tony McDade, and other Black citizens killed by police.

Since the protests began, demonstrators in multiple cities have reported spotting LRADs, or Long-Range Acoustic Devices, sonic weapons that blast sound waves at crowds over large distances and can cause permanent hearing loss. In response, two audio engineers from New York City have designed and built a shield which they say can block and even partially reflect these harmful sonic blasts back at the police.