One of my clients in South Africa (ZA) instituted a People Based Safety (PBS) program about four years back. As you recall this was the time the Football (soccer) World Cup was hosted by ZA in 2010. The Vuvuzela, a plastic horn that produces a loud bellowing sound, is a common noise-making tool for football spectators in ZA and the intensity of its use in the 2010 World Cup was impossible to miss. There were estimates that Vuvuzela use exceeded 120 dB during matches.
In one of the mine construction locations in the east of the country the PBS team were looking for ways to increase observations. Obviously the World Cup was on everyone's mind in this football-loving country. So the employees on the PBS team decided to use the ubiquitous horn in their campaign.
Here's how it worked: At random intervals during the work shift a PBS team member would blow a Vuvuzela, whose high bellow you could hear throughout the site. When the Vuvuzela was sounded, everyone who could safely stop work did so, and then did a behavioral safety observation on themselves or someone close to them. They were also encouraged to get a drink of fluid and adjust any PPE or guards. Turning in the observation cards was optional.
In that year, this site had the highest reduction of injuries of any project in the company's history.