Phonetics (pronounced /fəˈnɛtɪks/, from the Greek: φωνή, phōnē, ‘sound, voice’) is a branch of linguistics that comprises the study of the sounds of human speech, or—in the case of sign languages—the equivalent aspects of sign. It is concerned with the physical properties of speech sounds or signs (phones): their physiological production, acoustic properties, auditory perception, and neurophysiological status. Phonology, on the other hand, is concerned with the abstract, grammatical characterization of systems of sounds or signs.
The field of phonetics is a multilayered subject of linguistics that focuses on speech. In the case of oral languages there are three basic areas of study:
Articulatory phonetics: the study of the production of speech sounds by the articulatory and vocal tract by the speaker
Acoustic phonetics: the study of the physical transmission of speech sounds from the speaker to the listener
Auditory phonetics: the study of the reception and perception of speech sounds by the listener
These areas are inter-connected through the common mechanism of sound, such as wavelength (pitch), amplitude, and harmonics