It's just way too loud...

[GMGQ]

An alternative to stockmans/dursos, is to choke back the drain, so that your overflow sort of "overflows" to bring the water level a few inches above the drain hole. This results in a *silent* drain. Not even a single gurgle noise:

Drain:


But you must have a second drain that's a bit above the water level, in case the level fluctuates and goes too high (then that 2nd drain will kick in as an emergency drain).

Emergency Drain:


Wont work in everyone's setup, but if you can make it work, I'd highly suggest it. Now all I hear is the hum of my return pump. Sometimes it freaks me out because I dont hear the water trickle. I gotta open up the cabinet to make sure water is flowing through the sump. It's THAT quiet.