<P> Phonetics (pronounced / fəˈnɛtɪks /) is the branch of linguistics that studies 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 . </P> <P> In the case of oral languages, phonetics has three basic areas of study: </P> <Ul> <Li> Articulatory phonetics: the study of the organs of speech and their use in producing speech sounds by the speaker . </Li> <Li> Acoustic phonetics: the study of the physical transmission of speech sounds from the speaker to the listener . </Li> <Li> Auditory phonetics: the study of the reception and perception of speech sounds by the listener . </Li> </Ul> <Li> Articulatory phonetics: the study of the organs of speech and their use in producing speech sounds by the speaker . </Li>

What are the three main branches of phonetics