Sound Overload? Damn near crashes my game

It seems when the game is getting hectic and close to finishing, something causes the game and overall computer to slow down and lag, eventually becoming just “BEEPS” for every single input action (via keyboard or mouse), as to tell me inputs aren’t registering b/c of some malfunction.

This only happens in Overwatch. Only Overwatch. Any other games you might ask? Nope. Only happens on Overwatch. Maybe it’s your sound setup? Nope, my sound works for every other thing, its Overwatch. Fix it plz.