what inductors are used to reduce coil whine?
It's probably not the type of inductors that has changed much over the last 10 years or so that has reduced whining, but the higher frequencies used now, well above the audio range.
Higher frequencies in switching power supplies allow for smaller components, using less PCB space, and the trend has been in that direction, despite possible higher switching losses. Making them &quot;silent&quot; is a happy side effect.
Also, reducing inductor noise isn't a design criterium for all manufacturers; perhaps some do this better than others.
Apart from that, some physical form factors of inductors do whine more than others, and their mounting plays a role as well. I don't know if there are Special Super Silenttm inductors out there, though; I never noticed any advertised like that in suppliers' catalogues.
BTW if it really is driving you crazy, try applying a dab of glue or nail polish to the inductor in a few places and let dry; it tends to silence them.