True, the only thing I hear from my Aquaclears is sometimes water splashing. If the water level is high enough, not even that...
29g heavily planted SA: driftwood, Ram, Angel, Tetras
10g Tang: rock w/anubias, Caudpunk trio
8g Nuvo: Cherries, driftwood, java moss and fern
10g 3x divided Betta planted