Residents of Denver’s Montbello, Clayton, Villa Park and Westwood neighborhoods will hear gunshots tonight between 7 and 10 p.m. while police test the ShotSpotter gunfire detection system.

The Denver Police Department stressed in an announcement that there is no danger to the public. Bullets will be fired into a bullet trap, not into the air or on the ground.

The tests are for the currently installed ShotSpotter system, which Denver police have been using since 2015. The time frame for testing was chosen because most shootings and reports of shots fired happen at night and acoustics are different then, the department said.

The system involves a network of acoustic sensors — the locations of which are not disclosed — that can detect when a gun is fired, precisely determine the location of the gunfire and notify 911 dispatchers in less than a minute.

Since the department began using ShotSpotter, it’s resulted in 96 arrests and the recovery of 78 guns.