Phonology

Phonology is the subfield of linguistics that studies how sounds function within a particular language or across languages, identifying the small set of contrastive sound units, or phonemes, that speakers use to distinguish meaning and the rules that govern how those units combine and change in context. It differs from phonetics, which studies the physical production and acoustics of speech sounds in general, by asking which of those physical differences a given language actually treats as meaningful. Jacob Grimm's systematic study of Germanic consonant correspondences and Panini's analysis of Sanskrit sound classes are both counted among the field's early antecedents.