• “[Phonetics] is divided into three main branches, corresponding to these three distinctions:
    • articulatory phonetics is the study of the way the vocal organs are used to produce speech sounds
    • acoustic phonetics is the study of the physical properties of speech sounds
    • auditory phonetics is the study of the way people perceive speech sounds

    (David Crystal, The Cambridge Encylopedia of the English Language, 2nd ed. Cambridge Univ. Press, 2003)