Hahahahahahaha! “Anti-Sonar device”!!!!!!!
Don’t know if the frquencies above my hearing range messed with the bats navigation but the audible ramge was pretty damn loud. Would have been a great selfie video... big hulky guy, tennis racket in one hand, belt sander in the other trying to herd the bat to the open window...field expedient anti-sonar, sound chaff on the spur of the moment... What can I say? It worked
;>)