Never heard of it. I do let my kids run like little wild monsters in the yard near the horses though. And our Trampoline is where the horses can see and hear the kids scream and holler and bounce all over the place. We shoot guns in the yard maybe 100feet from the horses. I smack the bottom of the tub I use when I carry hay to the horses Every time I feed them. We do our very best to be loud around the horses when we are doing everyday things and then gentle and quiet and very attentive to the horse when we are handleing them. Even though the kids might still be loud in the background.
I use something similar. I have played it in the barn, round pen, and arena. I did see a reaction to the sounds the first few times I used it. Now they don't seem to care. I do not use it all the time because I don't want my horses to expect it.