The experiments with sound cannons, which are illegal in Serbia and several other countries, were reportedly carried out two weeks after anti-regime protests in Belgrade were interrupted by what protesters described as a "paralyzing sonic explosion."
The joint experiment, Politico notes, shows how far-reaching security cooperation is between Russia and EU candidate Serbia.
Sound cannons emit extremely loud sound waves that can cause severe earaches and headaches, disorientation, ruptured eardrums and permanent hearing damage.
Serbia has vehemently denied that sound cannons were used in connection with last year's widespread anti-government protests. Hundreds of protesters accused the government in March 2025 of using sound weapons against peaceful demonstrators.
Belgrade resident Ivana Ilic Sunderic described it as a "sound from hell."
"It was calm and quiet, and then we heard something we couldn't see ... like a sound rolling toward us," she told the AP news agency.
Protesters who went to the hospital said they heard a sound similar to an approaching train and then suffered from nausea, vomiting and headaches.
Two weeks later, the Serbian and Russian security services conducted animal tests to evaluate the sonic weapons' "effect on biological objects," Politico reports. Dogs were chosen because of their "sensitivity to acoustic effects."
According to Politico, the documents indicate that the tests were conducted without the permits required by Serbian law for animal testing.
