Phonetics: The study of speech sounds. Phoneticians study both the production of speech sounds by the human speech organs (articulatory phonetics) and the properties of the sounds themselves (acoustic phonetics). Phoneticians are concerned with such questions as: …What are the sounds, from among all those that humans could make, that actually exist in the world’s languages? …What specially defines different “accents”? …Can speakers be identified by “voiceprints”? ...What are the properties of sounds that would apply in computerized speech synthesis?
Phonology: The study of language sound systems. Phonologists are concerned with questions such as: …What sounds contrast in one language but not another (answers to such questions explain why Spanish speakers have trouble with the difference between English sh and ch, or why English speakers have trouble with the different “u” sounds in French words like rue ‘street’ and roue ‘wheel’.)? …What sounds of a language can or cannot occur one after the other (for example, why can words begin in st- in English but not in Spanish)? ...How do poets or writers or song lyrics intuitively know how to match the rhythm of speech to the abstract rhythmic pattern of a poetic or musical meter?