For the past year, Greece’s land border with Turkey, bounded by the fast-flowing Evros river, has been a focus for the country’s conservative government. Activists describe this heavily militarized area as a communications dead zone. Journalists and NGO workers struggle to access it and refugees trying to cross regularly have their phones confiscated by police. But some videos do escape through the cracks. Including desperate pleas from people stranded on islands in the middle of the river and grainy, seconds-long footage from inside government-run detention centers. 

In May, Greek police staged a press call near the border town of Feres to proudly show off their latest technological acquisition. Mounted on a vehicle, it looked like a large, grey tannoy — a little bigger than a megaphone, equipped with dials and colored buttons. Wearing earplugs, a police officer grabbed its handles and moved the device in different directions as it emitted a piercing alarm sound. 

“Our task is to prevent migrants from entering the country illegally. We need modern equipment and tools to do that,” said Police Maj. Dimosthenis Kamargios, head of the region’s border guard authority.

The model on show — the LRAD 450XL — is produced by Genasys, a leading U.S. company that has been developing long-range sonic devices, or sound cannons, for three decades. The 450XL is capable of emitting sound levels up to 150 decibels. Equivalent to having a shotgun blasted directly beside your ear, sounds of that volume are capable of causing permanent hearing loss.