音声学（Phonetics）：発音の物理的側面に関する研究

音韻論（Phonology）：音声の各言語における機能に関する研究

Phonetics – the study of the sounds that form human language – can be divided into two categories. The first type of phonetics, articulatory phonetics, examines the speech organs and processes by which humans produce sounds; the focus is on the speaker of language. The second type of phonetics, acoustic phonetics, focuses on the sound that is produced when a person speaks; the aim of acoustic phonetics is to understand the acoustic properties of speech, and how that speech is perceived by the listener’s ears.