To each his own but I would like to sit down with some of those people and do A/B testing with my system switching my cooling profiles between silent, full, and auto (I only use auto).
Full tower, i5 3570K@4.4GHz, huge air cooler, 8 low speed fans (6 120mm case, 2 140mm CPU), case has sound deadening applied.
Silent uses 4 fans (2 in 2 out) at 500rpm, full is self explanatory, and auto is temperature based which is the same as silent until CPU >60°c or
GPU >70°c at which time it turns other fans on depending on circumstance and starts speeding them up as need be.
There isn't any music that is going to load the system enough to raise the CPU above 60 so it stays virtually inaudible.