Phonology
The first person to use the word "phoneme" was the French linguist (one who studies language) A. Dufriche-Desgenettes. In the 1800s, Jan Baudoin gave the definition of phoneme that is uses today.Soon afterward, Baudouin de Courtenay began the study of phonology.and worked on the theory of phonetic alternations, which predicts changes in the sounds of a language.