Before long, the rat gives a fear response to the tone, as it has been conditioned to associate the sound with pain.
alisations - instead, we hear the meaning of the words.
When we hear music, our brains are imposing structure and order on a number of distinct sounds so that we experience them as a whole. It's a perceptual illusion that changes what we hear, much as we don't "hear" spoken language as a series of vocalisations - instead, we hear the meaning of the words.