1. Some people hear better than others.
2. Your definition of loud might not be the same as others.
3. Some sounds are more irratating to some than others.
I tend to consider loud if I can hear the drive above the sound of the fan(s). My fans are fairly quiet, but I can't hear my drives over them unless I put my head up to the case. Since I don't operate my computer with my ear to the case, I'm good with it.