[A1kmm]

If you had carefully synchronised low intensity sound sources close to all detectors, you could certainly simulate a gunshot and choose where it was triangulated to by controlling the timing and intensity of the sounds emitted by your multiple sources. Such a simulation could certainly be used to trick the system into thinking that there are hundreds of simultaneous major gun fights going on - which would obviously inhibit the ability of the police to respond to a real one, with a lot less manpower than calling in so many fights.

However, it would probably be more effort than it would be worth, so it is probably more a sci-fi / crime plot than a scenario that is likely to come up often.