You're trying to learn an eastern language and the teacher tells you four forms of a word, e.g ma, ma, ma, ma (each with different intonation/level). As an adul

You're trying to learn an eastern language and the teacher tells you four forms of a word, e.g ma, ma, ma, ma (each with different intonation/level). As an adult westerner you'll be lucky to differentiate two sounds out of the four; had you been practicing since a younger age you wouldn't have a problem. The same goes for your nose, in general your sense of smell is poor, but with training you can become better at it. Also why do you think everyone can perceive the maximum color/wavelength range that your eye can respond to? There are tetrachromatic women out there who can differentiate a lot more colors than a normal person can. This whole study/idea is just that we're basing language on that framework, and by having spent language on it we've spent more time to finely define it, which has caused us to become more skilled at it, etc.