1.5. Methods of Investigation Used in Phonetics

There are three principal methods: (1) the direct observation method; (2) the linguistic method; (3) the experimental method.

1. The direct observation method comprises three important modes of phonetic analysis: by ear, by sight and by muscular sensation. Investigation by means of this method can be effective only if the persons employing it have been specially trained to observe the minutest movements of their own and other people's speech organs and to distinguish the slightest variations in sound quality. Every phonetician undergoes a special training, in the course of which his "phonetic ear", and also his muscular sensation, are developed.

By a "phonetic ear" is meant the capability to distinguish the exact quality of sounds pronounced in various sound sequences or in isolation.

The muscular sensation is developed by constant and regular practice in articulating various sounds. A trained phonetician should be able to pronounce sounds of a given quality, as well as to re-cognize by means of his highly developed muscular sensation the exact nature of the articulation of any speech sound that he hears.

2. The aim of the linguistic method of investigation of any concrete phonetic phenomena, such as sound, stress, intonation or any other feature, is to determine in what way all of these phonetic features are used in a language to convey a certain meaning.

3. The experimental method is based upon the use of special apparatus or instruments, such as the laryngoscope, the artificial palate, the kymograph, the magnetic tape recorder, the oscillograph, the spectrograph, X-ray photography, slow motion films, as well as speech synthethizers.

Experimental methods first came into existence in the seventies of the 19th century. The well-known French phonetician, Rousselot, is considered to- be the originator of experimental phonetics. At about the same time, working quite independently, Prof. V. A. Bogoroditzky of Kazan, began experimental phonetic investigations with various instruments and apparatus. Thus, almost simultaneously, two laboratories of phonetic research were founded: one in Paris and the other in Kazan. Later (in 1899), the St. Petersburg laboratory was organized; there L. V. Shcherba performed his first experimental work on the Russian vowels.

Nowadays technical facilities have greatly developed, as a result of which technical methods are now frequently used in linguistics (e. g. machine translation, telephony and others). Owing to this, some linguists are of the opinion that the experimental method of investigation is the most important method, and that the direct observation and linguistic methods (especially the direct observation method) are obsolete. But it is not so. The method of direct observation may seem of secondary importance in studying European languages with which many people are familiar and which have already been thoroughly investigated. In the study of such languages or dialects that have not yet been fully investigated and described in books, the direct observation method and linguistic experimentation are the best and only methods to obtain desired results.

As for experimental methods, they should be utilized after certain linguistic facts have been ascertained and certain factual material has been collected. This material may require checking by means of some exact instruments or techniques.

Each branch of phonetics uses its own method of investigation, which changes (develops):

- articulatory phonetics uses method of direct observation, photography, cinematography, X-ray photography;

- in acoustic phonetics we use instrumental method. Two basic machines are called spectrograph and intonograph, nowadays computer software (programmes) is also used;

- in auditory phonetics we use methods of auditory/perception analysis (marking the text);

- the basic method in functional phonetics (phonology) is commutation or substitution, substituting sounds in different environments.

Generally in phonetic research we combine different methods.