phonetics

Phonetics is a branch of linguistics that mainly concerns the articulation and perception of speech sounds. The field of phonetics is traditionally divided into three sub-disciplines: articulatory phonetics, acoustic phonetics, and auditory phonetics. Linguists who specialize in studying these physical properties of talking or signing are phoneticians. Traditionally, the minimal linguistic unit of phonetics is the phone or a speech sound. It differs from the minimal linguistic unit of phonology, which is a phoneme. Phonemes are abstract categorizations of phones and are defined as the smallest units in any given language that affect meaning.

The communicative modality of a language describes the method by which its production and perception occurs. Languages using oral-aural modalities such as English produce speech orally (using the mouth) and perceive speech aurally (using the ears). Languages using manual-visual modalities such as Australian Sign Language (Auslan) and American Sign Language (ASL) produce sign manually (using the hands) and perceive sign visually (using the eyes). ASL and some other sign languages have in addition a manual-manual dialect for use in tactile signing by deafblind speakers where signs are produced with the hands and perceived with the hands as well. Phonetics also addresses equivalent aspects of sign languages and tactile signing are also studied.