Modifications of Vowels in Connected Speech

Date: 2015-10-07; view: 1309.

The modifications of vowels in a speech chain are traced in the following directions: they are either quantitative or qualitative or both. These changes of vowels in a speech continuum are determined by a number of factors such as the position of the vowel in the word, accentual structure, tempo of speech, rhythm, etc.

The decrease of the vowel quantity or in other words the shortening of the vowel length is known as a quantitative modification of vowels, which may be illustrated as follows:

1. The shortening of the vowel length occurs in unstressed positions, e.g. blackboard [ɔ:], sorrow [зu] (reduction). In these cases reduction affects both the length of the unstressed vowels and their quality.

Form words often demonstrate quantitative reduction in unstressed positions, e.g.

Is →he or ̖she to blame? – [hi:]

But: At →last he has ̖come. – [hi]

2. The length of a vowel depends on its position in a word. It varies in different

phonetic environments. English vowels are said to have positional length, e.g. knee – need – neat (accommodation). The vowel [i:] is the longest in the final position, it is obviously shorter before the lenis voiced consonant [d], and it is the shortest before the fortis voiceless consonant [t].

Qualitative modification of most vowels occurs in unstressed positions. Unstressed

vowels lose their “colour”, their quality, which is illustrated by the examples below:

1. In unstressed syllables vowels of full value are usually subjected to qualitative changes, e.g. man [mæn] – sportsman ['spɔ:tsmən], conduct ['kɒndəkt] – conduct [kən'd٨kt]. In such cases the quality of the vowel is reduced to the neutral sound [ə].

These examples illustrate the neutralized (reduced) allophones of the same phonemes as the same morphemes are opposed.

Nearly one sound in five is either [ə] or the unstressed [i]. This high frequency of [ə] is the result of the rhythmic pattern: if unstressed syllables are given only a short duration, the vowel in them which might be otherwise full is reduced. It is common knowledge that English rhythm prefers a pattern in which stressed syllables alternate with unstressed ones. The effect of this can be seen even in single words, where a shift of stress is often accompanied by a change of vowel quality; a full vowel becomes [ə], and [ə] becomes a full vowel. Compare: analyse ['ænəlaiz] – analysis [ə'nælisis].

2. Slight degree of nasalization marks vowels preceded or followed by the nasal consonants [n], [m], e.g. never, no, then, men (accommodation).

The realization of reduction as well as assimilation and accommodation is connected with the style of speech. In rapid colloquial speech reduction may result in vowel elision, the complete omission of the unstressed vowel, which is also known as zero reduction. Zero reduction is likely to occur in a sequence of unstressed syllables, e.g. history, factory, literature, territory. It often occurs in initial unstressed syllables preceding the stressed one, e.g. correct, believe, suppose, perhaps.

The example below illustrates a stage-by-stage reduction (including zero reduction) of a phrase.

Has he done it? [hæz hi· ,d٨n it]

[həz hi ,d٨n it]

[əz i ,d٨n it]

[z i ,d٨n it]