Methods and instruments of phonetic investigation.
The methods of investigation used in phonetics fall into three groups:
a) the methods of direct observation;
b) the experimental (instrumental) methods;
c) the linguistic methods.
The methods of direct observation comprise three modes of phonetic analyses: by ear (auditory), by sight (visual) and by muscular sensation. These methods consist in observing the movements and positions of one’s own or other people’s organs of speech in pronouncing various speech sounds, as well as in analyzing one’s own kinesthetic (muscular) sensations during the articulation of speech sounds and in comparing them with the resulting auditory impressions. It is oldest, simplest and most available method of investigation.
The experimental methods are based upon the use of special instruments and devices which include artificial palate, X-ray, laryngoscope, oscillograph, spectrograph, kymograph, intonograph. Due to these devices, the articulatory and acoustic properties of speech sounds are investigated. So, corresponding branches of phonetics are connected with technical sciences because they apply various technical achievements for the research work. The instrumental methods of investigation are:
- palatography which helps to determine the interaction of tongue and palate in production of speech sounds;
- X-ray photography and cinematography which help to trace the position and movement of speech organs;
- laryngoscopy which helps to observe the work of vocal cords;
- oscillography which helps to determine length, pitch and intensity of speech sounds;
- spectography which helps to obtain the general characteristics of a speech sound, it is very useful in investigation of complex sounds;
- kymography which helps to record qualitative variations of sounds;
- intonography which helps to measure the fundamental tone of the vocal cords, the average sound pressure, the duration of speech (pausation).
The usage of such device as the tape-recorder doesn’t imply in itself any instrumental analysis of the recorded speech, but serves the purpose of facilitating the speech analysis.
Methods of direct observation are rather subjective, whereas instrumental methods are objective. But these methods are complementary and not opposed to one another.
The aim of the linguistic methods of investigation is to determine in what way the phonetic phenomena, such as sound, syllable, stress, intonation are used in a language to convey a certain meaning.
Distributional analysis is the method of linguistic investigation which aim is to establish the distribution of speech sounds i.e. all the positions and combinations in which each speech sound of a given language occurs (or does not occur) in the words of that language. One of the steps of this analysis is substitution – the replacing of one speech sound by another in the same position to see whether a certain combination of sounds is possible or not.
The statistical method of linguistic investigation in phonetics is connected with the method of distributional analysis. Its aim is to establish the frequency, probably and predictability of occurrence of speech sounds in different positions in words.
The semantic method is used in phonetics to determine the phonological status of sounds. It consists in replacement of one sound for another in order to find out in which cases where the phonetic context remains the same such substitution leads to a change of meaning.