Lecture 1 Phonetics as a Linguistic Science Plan

5. The Acoustic Classification of English Vowels

Each vowel has its own acoustic spectrum, its own formant structure. The frequency of the formants and their position in the spectrum distinguish one vowel from another. The acoustic characteristics of vowels are based on their articulatory distinctions. Certain formants are characteristic of a particular volume, shape, and size of the resonators which produce a certain vowel. Thus, F1 is conditioned by the vertical position of the tongue. When the tongue is high in the mouth, F1 is low and vice versa. E.g. /i:/ and /u:/ have F1 in the region of 280-300 cps, whereas /ɑ:/ and /ɔ/ have F1 in the region of 600-800 cps. The second formant (F2) is conditioned by the horizontal position of the tongue and by the position of the lips. F2 is high in the case of a front vowel and it is low in the case of a back vowel. Thus /i:/ has F2 at about 2500 cps, where as /u:/ has F2 at about 900cps. F2 of rounded vowels is lower than of unrounded vowels, e.g. F2 of /ʌ/ is 1320 cps whereas F2 of /u / is 940 cps.

If the formants F1 and F2 are in the middle of the spectrum, i.e. close to each other as for /ɑ:, ɔ, æ/, the vowels are classified as compact. If the formants are at each of the extremities of the spectrum as for /u:, u, i:, I/ the vowels are diffuse. Open vowels are compact, close vowels are diffuse.

If the second formant is high, as for /i:, e/, the vowels are of a clear or acute timbre. If it is low, so that both F1 and F2 are in the low section of the spectrum (as for /u:, u, ɔ:/, a vowel has a dark or grave timbre. Front vowels are acute, back vowels are grave. F2 is lower in rounded vowels (as ɔ, ɔ:, u, u:) than it is in unrounded vowels (as i:, I, e, æ, ʌ, ɑ:). Acoustically, rounded vowels are opposed to unrounded as flat to plain.

Thus, from the point of view of their acoustic characteristics, the vowel /e/, for instance, is described as acute, compact, and plain. The vowel /ɔ/ is compact, grave and flat, and /u:/ is diffuse, grave and flat.
6. Unstressed Vowels in English

As stated above the unstressed vocalism of, English includes all vowel phonemes and the neutral phoneme /ə/ which appears as a result of weakening of the vowels in the unstressed position. The vowel /ə/ articulated by weak articulatory affect, has an indefinite tamber and changes its quality under the influence of neighbouring sounds depending on its position, and in certain positions it may be omitted. Therefore, it may have different variations distinct from each other, especially, by the height of the tongue and duration. The X-ray picture of /ə/ in a cat /ə`kæt/ shows that this vowel may be classified as mixed, mid-broad variation, unrounded (either lips are spread or neutral) vowel. Usually linguists distinguish from two to four variations of /ə/.

The neutral vowel, which appears in final unstressed position, is somewhat close to the tamber of the vowel /ʌ/, perhaps, to the Russian /a/ and the Uzbek /a/, but is shorter than they are: worker /wə:kə/ matter /mætə/etc.

The next version of /ə/ is used in initial and median unstressed positions except the neighbouring /k/ and /g/. This type of /ə/ is pronounced by a higher position of the tongue than in the first version: announce /ə`nauns/, about /ə`baut/. These two versions of /ə/ are regarded basic in practical studying of English.

The version of /ə/ used by the neighbouring /k/ and /g/ is regarded to be a very short and back, close-narrow variation: continue /kən`tInju:/, aggregate /ə`grIgeIt/.

The fourth version occurs before the consonants /z/ and /d/ which are used as morphemes expressing the plural form of nouns and the tense of verbs: matters /mætəz/, hunters /hʌntəz/, covered /kʌvəd/. It resembles /3:/ though it is pronounced half-long.

All these versions have different degrees of laxity. They are notated by the symbols /əʌ, ə3, əu, ə/.

They all represent the reduced forms of the neutral vowel /ə/, as they all occur in unstressed positions under the influence of reduction. Weakening of the unstressed syllables, as a result of which vowels (sometimes, consonants) change their quality and quantity features, is called reduction. The shortening of the vowel-length in unstressed position is known as a quantity reduction, while the omission of the clear tamber of a vowel is termed as a quality reduction. The most widespread type of quality reduction is neutralization, used in the phonetic but not phonological sense. The vowels of the neutral tamber have features similar to vowels with a certain quality called “cardinal tambers” by A.L.Trakhterov. Speaking about /ə/ it is better to describe it as “neutral tamber”, than “neutral position” of speech organs. Usually “neutral position” is used to describe the configuration of the speech organs just prior to a certain articulation of a speech sound. In a neutral position the velum is raised and the air-flow through the nose is shut off. Such a universal neutral position does not exist in the articulation of any speech sound. However, some linguists consider that the sounds /æ/, /3:/, /ʌ/, /e/, /ə/ may be produced by a neutral position. The neutral position stated above is possible in “hesitation vowels”, interpreted also as a “ vocalic filled pause” which is defined as having a (+vocalic,-consonantal) feature. X-ray pictures of the articulation /ə/ do not show any neutral position of the speech organs. Thus /ə/ is called a neutral vowel not for its articulation by the “neutral position”, but owing to the fact that during its articulation it has a neutral, non-distinct tamber or quality which is significant.

Besides the neutral vowel /ə/ there is an unstressed /I/ which is regarded as an unstressed allophone of the English phoneme /I/. The unstressed /I/ is used in unstressed syllables, in prefixes, in medial and final positions: mischief /mIsti:f/, abdicate /ə`bdIkeIt/, infinite /In`fInIt/, discover /dIs`kʌvə/, impose /Im`pəuz/, enjoy /In`ʤɔI/, credit /`kredIt/ etc. It should be stated that the neutral vowel /ə/ may often be omitted in colloquial rapid style of speech, but never so in the unstressed /I/: cotton /kɔt(ə)n/, London /lʌnd(ə)n/, darkness / dɑ:knIs/, sausage /sɔ:sIʤ/ etc. According to their occurance some authors distinguish vowels of: 1) full formation; 2)semi-weak vowels, i.e. those which take an intermediate position between strong vowels and the neutral /ə/ and 3) weak vowels. The idea of the semi-weak vowels have been made clear by G.P. Torsuyev and V.A. Vassilyev: “From the distributional point of view a semi-weak vowel… be defined as a partially reduced vowel which is used in more careful style of pronunciation instead of the neutral vowel used in the rapid colloquial style and instead of the corresponding vowel of full formation used in the full style”. All the unstressed vowels of constantly full formation are used in all styles of pronunciation and even in many words of foreign origin, especially Latin and Greek, which have not yet been fully adopted in English: insect /Insekt/, epochs /i:pɔks/, diagram /daIəgræm/,marquee /mɑ:ki:/ etc.

The vowels of constantly full formation have a relatively stable quality and may preserve their less clear tamber in an unstressed position: apple-tree /`æpltri:/, architect /`ɑ:kItekt/, objective /əb`jektIv/, artistic /ɑ:`tIstIk/, programme /prəu`ræm/, ensign /en`saIn/, upturn /ʌp`t3:n/, Uganda /u:gændə/, obey /əu`beI/, idea /aI`dIə/ etc.`