A popping balloon can sound like a gunshot. I was at a resort earlier this year where there was a shooting, and 2 hours later the entertainment staff was popping balloons and guests were diving for cover.
A memory from the 90s...
Almost everybody, including me, ducked when steam popped a kid’s balloon as we all were going thru the line at Morrison’s cafeteria.
Laughter followed... but not until we figured out what the hell it was.