The sequence of syllables in the word is not pronounced identically. The syllable or syllables which are uttered with more prominence than the other syllables of the word are said to be stressed or accented. Stress in the isolated word is termed word stress; stress in connected speech is termed sentence stress.
Stress is defined differently by different authors. B.A.
Bogoroditsky, for instance, defined stress as an increase of
energy, accompanied by an increase of expiratory and articulatory
activity. D. Jones defined stress as the degree of force, which is
accompanied by a strong force of exhalation and gives an impression
of loudness. H. Sweet also stated that stress, is connected with
the force of breath. According to A.C. Gimson, the effect of
prominence is achieved by any or all of four factors: force, tone,
length and vowel colour.
If we compare stressed and unstressed syllables in the words
contract ['kσntrækt], to contract [kən'trækt], we may note that in
the stressed syllable:
(a) the force is greater, which is connected with more energetic
(b) the pitch of voice is higher, which is connected with stronger
tenseness of the vocal cords and the walls of the resonance
(c) the quantity of the vowel [æ] in [kən'trækt] is greater, the
vowel becomes longer;
(d) the quality of the vowel [æ] in the stressed syllable is
different from the quality of this vowel in the unstressed
position, in which it is more narrow than ['æ].
On the auditory level a stressed syllable is the part of the word
which has a special prominence. It is produced by a greater
loudness and length, modifications in the pitch and quality. The
physical correlates are: intensity, duration, frequency and the
formant structure. All these features can be analyzed on the
acoustic level. Word stress can be defined as the singling out of
one or more syllables in a word, which is accompanied by the change
of the force of utterance, pitch of the voice, qualitative and
quantitative characteristics of the sound, which is usually a
vowel. In different languages one of the factors constituting word
stress is usually more significant than the others. According to
the most important feature different types, of word stress are
distinguished in different languages.
1) If special prominence in a stressed syllable or syllables is
achieved mainly through the intensity of articulation, such type of
stress is called dynamic, or force stress.
2) If special prominence in a stressed syllable is achieved mainly
through the change of pitch, or musical tone, such accent is called
musical, or tonic. It is characteristic of the Japanese, Korean and
other oriental languages.
3) If special prominence in a stressed syllable is achieved through
the changes in the quantity of the vowels, which are longer in the
stressed syllables than in the unstressed ones, such type of stress
is called quantitative.
4) Qualitative type of stress is achieved through the changes in
the quality of the vowel under stress.
English word stress is traditionally defined as dynamic, but in
fact, the special prominence of the stressed syllables is
manifested in the English language not only through the increase of
intensity, but also through the changes in the vowel quantity,
consonant and vowel quality and pitch of the voice.
Russian word stress is not only dynamic but mostly quantitative and
qualitative. The length of Russian vowels always depends on the
position in a word.
Now we should like to distinguish the notions of word stress and
sentence stress. They are first of all different in their sphere of
application as they are applied to different language units: word
stress is naturally applied to a word, as a linguistic unit,
sentence stress is applied to a phrase. Secondly, the distinction
of the rhythmic structure of a word and a phrase is clearly
observed in the cases when the word stress in notional words is
omitted in a phrase, e.g. I 'don't think he is 'right or when the
rhythmic structure of the isolated word does not coincide with that
of a phrase, e.g. 'Fifteen. 'Room Fifteen. 'Fifteen 'pages.
So in a speech chain the phonetic structure of a word obtains
additional characteristics connected with rhythm, melody, and
tempo. Though the sentence stress falls on the syllable marked by
the word stress it is not realized in the stressed syllable of an
isolated word but in a word within speech continuum. Since the
spheres of word stress and sentence stress fall apart their
functions are actually different. Sentence stress organizes a
sentence into a linguistic unit, helps to form its rhythmic and
intonation pattern, and performs its distinctive function on the
level of a phrase.
Stress difficulties peculiar to the accentual structure of the
English language are connected with the vowel special and inherent
prominence. In identical positions the intensity of English vowels
is different. The highest in intensity is /a:/, then go /о:, з:,
i:, u:, æ, σ, e, υ, i/.
All English vowels may occur in accented syllables, the only
exception is /ə/, which is never stressed. English vowels /i, и, ə
υ/ tend to occur in unstressed syllables. Syllables with the
syllabic /1, m, n/ are never stressed. Unstressed diphthongs may
partially lose their glide quality. In stressed syllables English
stops have complete closure, fricatives have full friction, and
features of fortis/lenis distinction are clearly defined.
Nature of word stress