The high end has definitely rolled off, and I have a bit of a kind of "fan running in the background" tinnitus. No problem with the low notes, though my speakers don't have deep bass anyhow, and I haven't invested in a sub-woofer, yet.
But can I hear the difference between my big speakers (Magnapan 1.6's) and a coke can sized speaker (or the average speaker)? Absolutely.
Way off topic, but I've noticed just cupping my hands around my ears (the way people do to hear a person speaking to them better) brings the highs back to how I remember them. I've actually thought about making up a sort of headband to wear, with cup-type reflectors behind my ears, or mounting something like that to the back of my listening chair. Googling those terms just leads to chairs with speakers built in, or some form of headphone.
-ERD50