Psychocoustics is a bit more complicated that. It has sort of been a hobby of mine for 40 or so years. The question is: What clues will make your brain believe what it is hearing is real? Handy perspective to a speaker builder hobbyist.
So on eq,
I did not really say it will filter them out, It will recognize the signature of the room and make overall adjustments as it accepts the environment over time.
As an example, when I first set up my audio all over this house. Different speakers, several rooms. The eq was drastically different room to room. About two weeks later, you could walk from my BR with Boston wall plates, to the living room with Paradigms, office with Kef's, guest room with my own and so on without noticing large differences in overall character. This is my brain remembering the rooms signature.
Second example. I replaced some Warfdales in one room with a new pair of mine, spent days playing with the absorbers, angles, crossovers etc. Got it pretty darn flat for the fixed listening position. Much brighter than the old Diamonds. Walk into the room, BANG, bright. A week later, the room signature is re-calibrated in my head. I do not hear an overall timber difference between rooms. I do hear the better detail and articulation as the new speakers are quite a bit lower in distortion.
That said, you may walk into the very same rooms and detect the guest room is bright, living a bit pushy in the upper mids, office a bit dull. YOUR brain is not calibrated to the signatures in my house. This makes EQ very important in public settings.
Again, big peaks are bad news whatever. Dips if not too wide, you can't hear even right off.
So, my postulate is that electronic eq within your accustomed listening environment is not that important. Flat lines on a chart do not convince me what I am hearing is music. Least we forget: Playing a real instrument in the very same room will have the same eq issues as playing a speaker. Spend your money on room treatments and better speakers, not eq. Or just buy more music.
"not always transparent". Understatement of the year. ( IMHO)