im not sure because i get coil whine from one of my 670's, but im pulling them out today and shipping them off to a lucky new owner.
but maybe ill be able to hear it now if it does have a coil whine.
i'll report back if i ever do hear it
I don't hear higher frequencies as well as I used to, but that's just due to my night-time job being one where I work in a bar. So loud noises have very minorly damaged my hearing. I can still hear them, but they're more faint.
On the other hand, I know someone who's a 35 year old sound engineer who's never been in a situation where his hearing has been exposed to such loud noise long term. Thus his hearing is almost perfect.
Well, I was just going by what others have said on here, and if the coil whine is high enough in pitch, then it will be impossible for some to people to hear. There are audio tests on the internet that can show you exactly what your hearing limit is. They also explain what I just said about age. Unfortunately, I don't have a clue of how I found those tests, meaning the ones that also explain that as you reach your late teens and early 20s, you can no longer hear these frequencies.
So anyway, again, if the pitch of your coil whine is above your hearing limit (in terms of frequency), then you are not going to hear it.