I've always been bothered by "zipper clink". Even if it's on the backpack of the guy in front of me as I walk down the aisle of a plane.
As a matter of procedure, I cut the metal "handle" off just about every zipper and replace with knotted cordage or a fancy molded option.
Sound bags, backpacks, jackets. Pretty much everything.
Added bonus is the weight savings. It's minimal of course, but you might be surprised by the small heft of die-cast metal waste in your
hand as you toss it in the bin.