I don’t know where in history it became unacceptable to let out a grunt while lifting weights or to drop your dumbbells on the floor. People working out are loud, it’s not your fucking privilege to have a low decibel level in a gym. Even if I was screaming, who is it hurting? Gyms should be expected to be more of a loud environment. Silence should be the exception not the norm, people who want silence are the minority and they should have to schedule their quiet times in a manner that doesn’t interfere normal every day gym goers.
Sounds like you have a club in the making already. You can call it the Loud Lifters and become petty bourgeois (make your own CrossFit-like space since they're already loud).
Instead of a lunk alarm, they have an alarm that goes off if the ambient noise goes below, say, lawnmower at 8 am Sunday morning.