Have you considered water cooling? The heat is, of course, still going to get dissipated, but the noise should become much less of an issue. As a bonus, idle temps should drop close to room temperature.

I don't like the idea of maintaining an open loop myself (changing the liquid every 6-12 months), but there are also half-measure options like all-in-one (AIO) coolers. Most of them aren't serviceable (can't refill them), but they should still last for five years or so. That mostly for CPUs, though, AIO GPUs are somewhat rare (but they do exist!).

edit: confused open and closed loops