I didn't downvote you, but your message is a bit useless: I know lots of people that feels the most bizarre things when they know about it. Starting with people

I didn't downvote you, but your message is a bit useless: I know lots of people that feels the most bizarre things when they know about it. Starting with people that believe in magic (like in if you burn a black candle, you get free from bad luck), to a girl that got the ear pierced in at least a dozen points to relieve pain on random points of the body. According to her, it worked. A woman who claims that every single chemical puts her in agonizing pain, but sure enough the pain only starts when he knows the chemical is there. My point is you should try randomly at least couple of headphones that some other person removed the foam on one of them without you even knowing. Then you could apply some simple test like the binomial, and claim/reject one of them gives you headaches. Quality of sound has a abjective part (a speaker too loud would sound broken to every one), and a heavy subjective part (a speaker with too much bass would sound great to some, bad to others). If someone say "this headphones sound bad" it means almost nothing. I hate the sound of every guitar with single coil pickups, even the most expensive Fender Tele/Strato, but a lot of guitarist love their sound. I cannot claim "the single coil sounds worse" as if it was an objective thing that everyone should agree to, because what I really mean is "I don't like single coils".