Phonetics is the systematic study of the human ability to make and hear sounds which use the vocal organs of speech, especially for producing oral language. It is usually divided into the three branches of (1) articulatory, (2) acoustic and (3) auditory phonetics. It is also traditionally differentiated from (though overlaps with) the field of phonology, which is the formal study of the sound systems (phonologies) of languages, especially the universal properties displayed in ALL languages, such as the psycholinguistic aspects of phonological processing and acquisition.
One of the most important tools of phonetics and phonology is a special alphabet called the International Phonetic Alphabetor IPA, a standardized representation of the sounds used in human language. In this chapter, you will learn what sounds humans use in their languages, and how linguists represent those sounds in IPA. Reading and writing IPA will help you understand what's really happening when people speak.