Toronto Police will keep the four sound cannons used during the G20 summit.

The decision was announced at a board meeting Thursday night.

Chief Bill Blair said the controversial devices, which emit ear-piercing blips and can broadcast messages, will be used for communication purposes.

The Marine Unit will get one cannon, the public safety unit will get two, and Toronto Ire will have the fourth.

During the G20 summit, protesters won a temporary injunction banning authorities from using sound cannons as a crowd control device.

Justice David Brown ruled that there was a real chance that the controversial long-range acoustic devices, or L-RADs, could cause hearing damage.

However, Toronto Police can use the devices for communication purposes or “voice function.” As well, the OPP can use the alert function at more modest decibel levels and distances.