Phonetics is not a new science. It was known to the ancient Greeks and to the ancient Hindus. The scientists of that time were concerned with speech sounds only. It may be said that the orthography of all written languages which use alphabets developed in the course of a very detailed phonetic analysis.
Nevertheless, phonetics, as an independent science, began to develop in western Europe and in Russia only in the 19th century. There has been considerable progress and growth in the 20th century. Within the last half century especially, new concepts have sprung up, new theories and new schools have come into existence, new methods of investigation have been developed.
Several new branches of phonetics have also arisen. The most important of these are special phonetics and general phonetics.
Special phonetics may be subdivided into descriptive phonetics and historical phonetics. Special phonetics is concerned (1) with the study of the phonetic structure of one language only, in its static form, at a particular period, synchronically (descriptive phonetics); (2) with the study of the phonetic structure of a language in its historical development, diachronically (historical phonetics).
General phonetics is based on the extensive material which the special phonetics of a great number of languages provides; it is also based on other sciences, such as physics, biology, psychology, speech pathology, etc. It has been able to analyse speech sounds from different points of view and to formulate a number of important theories: the phoneme theory, the theory of syllable formation, theories connected with syntagm, stress, intonation, graphical rules and rules of orthography, etc.
On the one hand, general phonetics is based on the data of special phonetics; on the other hand, general phonetics provides valuable theoretical material which enables us to understand clearly and to interpret correctly the different phonetic phenomena of concrete languages.
Closely connected with historical phonetics is comparative phonetics whose aims are to study the correlation between the phonetic systems of two or more languages and find out the correspondences between the speech sounds of kindred languages.
Phonetics can also be theoretical and practical. At the faculties of Foreign Languages in this country, two courses are introduced:
1. Practical, or normative, phonetics that studies the substance, the material form of phonetic phenomena in relation to meaning.
2. Theoretical phonetics, which is mainly concerned with the functioning of phonetic units in language.
We know that the phonic medium can be studied from four points of view: the articulatory, the acoustic, the auditory, and the functional.
We may consider the branches of phonetics according to these aspects. Articulatory phonetics is the study of the way the vocal organs are used to produce speech sounds. Acoustic phonetics is the study of the physical properties of speech sounds. Auditory phonetics is the study of the way people perceive speech sounds, in other words, it investigates the hearing process. Of these three branches of phonetics, the longest established, and until recently the most highly developed, is articulatory phonetics. For this reason, most of terms used by linguists to refer to speech-sounds are articulatory in origin.
Phoneticians are also interested in the way in which sound phenomena function in a particular language. In other words, they study the abstract side of the sounds of language. The branch of phonetics concerned with the study of the functional (linguistic) aspect of speech sounds is called phonology.
Phonology is quite a controversial subject. By the middle of the XXth century the term "phonetics" has become somewhat ambiguous. This is largely due to the Prague School of Linguistics which propagates a new science phonology, that is to be differentiated from phonetics. According to the conceptions of the Prague School, phonetics and phonology are two independent branches of science. Phonetics is a biological science, and is concerned with the physical and physiological characteristics of speech sounds. Phonology is a linguistic science, and is concerned with the social functions of different phonetic phenomena. The Prague School of Linguistics has many adherents. As a result of this, the term "phonology" is now widely used by linguists of many countries and refers to that part of linguistics which makes a study of all phonetic phenomena from the point of view of their social significance.