Used on artillery practice ranges. Germany is densely populated and local population complained about the noise from the firing locations. The solution was silencers for the firing locations, now only the target area needs to be in “remote” locations.
In Switzerland they tested mufflers, sized like oil barrels, for their Leo tanks. Some tank officer commented that the costs for minor accidents (fender benders) had gone down since the easily damaged mufflers immediately identified the tank whose driver needed further training.