Let me devils advocate this a little, but if this were true wouldn't it stand to reason that every time someone spent more money on something or just something new trying to perceive an upgrade if their brain was telling them it should sound better wouldn't that upgrade always sound better to them?

If so then why do some people get new things and it sounds worse?

Again devils advocate, but curious as to how that's explained because if someone's upgrade something and the mind is so powerfully is controls how something sounds to you then that upgrade should always sounds better because the brain is telling you it should. Right?