I am taking an introduction course about linguistics. When my teacher was trying to explain the difference between phonetics and phonology she said something like: "PHONETICS is study of physical reality of sound, PHONOLOGY is study of psychological reality of sound"
That´s totally not explanatory for me. What does it mean that a sound has a psychological reality?
Fortunately, Sapir's classic The Psychological Reality of Phonemes is available on line for free. I'm sure you'll find it interesting.
I don't think your teacher's characterization of phonology is very good. While many phonologists would probably agree with Sapir's contention that phonemes are psychologically real, on the other hand, they would be chagrined to learn that they are not studying physical reality. It's probably the idea of some phoneticians that anything mental is not physically real, but few others would subscribe to it.
That kind of sound bite is common in the profession, but is also wrong. Phonology is about a particular cognitive process where language sounds are studied as units which are made up of yes-no categories. For example, in forming the 3rd person present of a verb in English, the suffix /z/ is added, but it is changed to s when the preceding sound is f,θ,p,t,k; and the vowel ɨ is inserted when the preceding sound is s,z,ʃ,ʒ. Phonology studies these rules. Phonetics studies the a number of things about how we produce such sounds (acoustics, articulation), but it is also involved in the psychology of articulation and perception. So it is wrong to deny that phonetics studies sound from a psychological perspective.
