I've got a pair (well, actually TWO pair) of the older KOSS PRO-4AA's:
one at the office the other at home. They'll even seal out your
mother-in law! Unfortunately, after wearing them for a while they
feel as HEAVY as your mother-in-law.
I remember that for years the PRO-4, -4A and -4AA were the reference
to which other headphones were reviewed..."The XXX's didn't have the
bass respones of the PRO-4A but were almost as smooth in the mid- and
upper-ranges..." Of course, this was maybe 15 years ago. Oh, well.
I like 'um.
keith