Phonetic notation systems have long been used as an essential tool in the phonetic description of languages of the world and also more generally in other branches of the linguistic sciences. In this essay, one of the most widely used phonetic transcription systems will be discussed in detail, i.e. the alphabet of the International Phonetic Association, firmly rooted in a strong international phonetic tradition which emerged in the last decades of the 1800s. Phonetics can be appropriately regarded as the study of the medium of spoken language. Phonetic notation specifically transforms the aural medium into a visual or tactile medium to provide an accurate and permanent record of the ways in which speech sounds are produced in languages (articulation). Furthermore, such representation also indicates what these speech sounds sound like (perception). Phonetic notation thus informs both about the speech production and the speech perception processes involved in the aural medium.