Phonetics -Definition
Phonetics is the scientific study of speech. It has a long history, going back certainly to well over two thousand years ago. The central concerns in phonetics are the discovery of how speech sounds are produced, how they are used in spoken language, how we can record speech sounds with written
symbols and how we hear and recognise different sounds. In the first of these areas, when we study the production of speech sounds we can observe what speakers do (articulatory observation) and we can try to feel what is going on inside our vocal tract (kinaesthetic observation).
The second area is where phonetics overlaps with phonology: usually in phonetics we are only interested in sounds that are used in meaningful speech, and phoneticians are interested in discovering the range and variety of sounds used in this way in all the known languages of the world. This is sometimes known as linguistic phonetics.
Thirdly, there has always been a need for agreed conventions for using phonetic symbols that represent speech sounds; the International Phonetic Association has played a very important role in this. Finally, the auditory aspect of speech is very important: the ear is capable of making fine discrimination between different sounds, and sometimes it is not possible to define in articulatory terms precisely what the difference is. A good example of this is in vowel classification: while it is important to know the position and shape of the tongue and lips, it is often very important to have been trained in an agreed set of standard auditory qualities that vowels can be reliably related to (see cardinal vowel; other important branches of phonetics are experimental, instrumental and acoustic).
(Peter Roach, 2002:58)
Three basic approaches to the study of phonetics may be mentioned
–Articulatory phonetics is concerned with the position, shape and movements of speech articulators
–Acoustic phonetics is concerned with the spectro-temporal properties of the speech sound waves
–Auditory phonetics is concerned with the perception, categorization, and recognition of speech sounds and the role of the auditory system
Articulatory phonetics (vowels)
Vowels can be described in a similar way
–Manner of articulation, just considered to be “vowel”
–Place of articulation is generally described with three major parameters: frontness, height, and roundness
1- Frontness (or backness)
–Three positions in English
•Front: [i:] beat, [bIt] bit, [ae] bat
•Central: “schwa” *ax+ about
•Back: [uw] boot, [ao] bought, [ah] but, [aa] father
2- Height
–Refers to how far lower jaw is from upper jaw when making the vowel
•High vowels have lower and upper jaw close: [iy], [uw]
•Low vowels have a more open oral cavity: [ae], [aa]
–Correlates with F1 (high vowel: low F1; low vowel: high F1)
3- Roundness
–Refers to whether the lips have been rounded as opposed to spread
–In English, front vowels are unrounded whereas back vowels are rounded: bit vs. boot
Acoustic phonetics
An important part of phonetics is the study of the physics of the speech signal: when sound travels
through the air from the speaker’s mouth to the hearer’s ear it does so in the form of vibrations in the air. It is possible to measure and analyse these vibrations by mathematical techniques, usually by using specially-developed computer software to produce spectrograms. Acoustic phonetics also studies the relationship between activity in the speaker’s vocal tract and the resulting sounds. Analysis of speech by acoustic phonetics is claimed to be more objective and scientific than the traditional auditory method which depends on the reliability of the trained human ear.
Auditory phonetics
When the analysis of speech is carried out by the listener’s ear, the analysis is said to be an auditory one, and when the listener’s brain receives information from the ears it is said to be receiving auditory information. In practical phonetics, great importance has been given to auditory training: this is sometimes known as ear-training, but in fact it is the brain and not the ear that is trained. With expert teaching and regular practice it is possible to learn to make much more precise and reliable
discriminations among speech sounds than untrained people are capable of. Although the analysis of
speech sounds by the trained expert can be carried out entirely auditorily, in most cases the analyst also tries to make the sound (particularly when working face to face with a native speaker of the language or dialect), and the proper name for this analysis is then auditory-kinaesthetic
Cardinal vowel
Phoneticians have always needed some way of classifying vowels which is independent of the vowel
system of a particular language. With most consonants it is quite easy to observe how their articulation is organised, and to specify the place and manner of the constriction formed; vowels, however, are much less easy to observe. Early in the 20th century, the English phonetician Daniel Jones worked out a set of "Cardinal Vowels" that students learning phonetics could be taught to make and which would serve as reference points that other vowels could be related to, rather like the corners and sides of a map.
Phonetic "ear-training" makes much use of the Cardinal Vowel system, and students can learn to
identify and discriminate a very large number of different vowels in relation to the Cardinal vowels.
vowels
Vowels include the sounds we ordinarily represent as the letters <a, e, i, o, u>, as well as a number of other sounds for which the ordinary alphabet has no unique symbols. Vowels are distinguished from consonants in several ways. Consonants are produced by constricting the airstream to various degrees as it flows through the oral tract. Vowels are produced with a smooth, unobstructed airflow through the oral tract.
Differences in vowel quality are produced by different shapes of the oral cavity. Characteristic vowel qualities are determined by (a) the height of the tongue in the mouth; (b) the part of the tongue raised (front, middle, or back); (c) the configuration of the lips; and (d) the tension of the muscles
of the oral tract. An articulatory description of a vowel must include all of these features.
