What is practical and theoretical phonetics? What do they study?

Practical or normative phonetics studies substance, the material form of phonetic phenomena in relation to meaning.
Theoretical phonetics is mainly concerned with the functioning of phonetic units in the language.
Phonetics studies the sound system of the language, that is segmental units (phonemes, allophones), suprasegmental units (word stress, syllabic structure, rhythmic organization, intonation). Phonetics is closely connected with general linguistics but has its own subject matter (Investigation).
Thus phonetics is divided into two major components: segmental phonetics, which is concerned with individual sounds (i.e. "segments" of speech), their behaviour; and suprasegmental phonetics whose domain is the larger units of connected speech: syllables, words, phrases and texts.

THEORETICAL PHONETICS (лекции)

1. Theoretical phonetics as science. Branches of phonetics. Methods of investigation.
Phonetics is concerned with the human noises by which the thought is actualized or given audible shape: the nature of these noises, their combinations, and their functions in relation to the meaning.
Practical or normative phonetics studies substance, the material form of phonetic phenomena in relation to meaning.
Theoretical phonetics is mainly concerned with the functioning of phonetic units in the language.
Phonetics studies the sound system of the language, that is segmental units (phonemes, allophones), suprasegmental units (word stress, syllabic structure, rhythmic organization, intonation). Phonetics is closely connected with general linguistics but has its own subject matter (Investigation).
Thus phonetics is divided into two major components: segmental phonetics, which is concerned with individual sounds (i.e. "segments" of speech), their behaviour; and suprasegmental phonetics whose domain is the larger units of connected speech: syllables, words, phrases and texts.
All speech sounds have 4 aspects (mechanisms):
- Articulatoty – it is the way when the sound-producing mechanism is investigated, that is the way the speech sounds are pronounced
- Acoustic – speech sound is a physical phenomenon. It exists in the form of sound waves which are pronounced by vibrations of the vocal cords. Thus each sound is characterized by frequency, certain duration. All these items represent acoustic aspect.
- Auditory – sound perception aspect. The listener hears the sound, percepts its acoustic features and the hearing mechanism selects from the acoustic information only what is linguistically important. .http://youreng.narod.ru/teorph.html

PHONETICS (Gr. xcovi, voice), the science of speech-sounds and the art of pronunciation. In its widest sense it is the "science of voice," dealing not only with articulate, but also with the inarticulate sounds of animals as well as men. The originally synonymous term, "phonology," is now restricted to the history and theory of sound-changes. The most obvious of the practical applications of phonetics is to the acquisition of a correct pronunciation of foreign languages. But its applications to the study of the native language are not less important: it is only by the help of phonetics that it is possible to deal effectively with vulgarisms and provincialisms of pronunciation and secure uniformity of speech; and it is only on a phonetic basis that the deaf and dumb can be taught articulate speech. From a more theoretical point of view phonetics is, in the first place, the science of linguistic observation. Without phonetic training the dialectologist, and the missionary who is confronted with a hitherto unwritten language, can neither observe fully nor record accurately the phenomena with which they have to deal. These investigations have greatly widened the scope of the science of language. The modern philologist no longer despises colloquial and illiterate forms of speech. On the contrary, he considers that in them the life and growth of language is seen more clearly than in dead literary languages, on whose study the science of comparative philology was at first exclusively built up. It was not till philologists began to ask what were the real facts underlying the comparisons of the written words in Sanskrit, Greek, Latin, and the other Indo-European languages,. embodied in such generalizations as Grimm's Law, that "letter-science" developed into "sound-science" (phonology). The rise and decay of inflexions, and the development of grammatical forms generally, are, from the formal point of view, mainly phonetic problems; and phonetics enters more or less into every department of historical and comparative grammar. <a rel="nofollow" href="<a rel="nofollow" href="