On the nature of stress

When syllables are uttered in sequence, in polysyllabic words, for example, they are perceived as having different degrees of prominence, or stress. In each of the following words one syllable is stressed, the other(s) unstressed: 'sequence, pho'nology, per'ceive. In many words, the prominence of syllables is further differentiated; thus in polysyl'labic, kanga'roo, hal,luci'natory the syllables marked ‘,’ bear secondary stress: stress that is weaker than the main (or ‘primary’) stress but stronger than that of an unstressed syllable. In longer words, further differentiation of stresses can be found: in ,anti,dises,tablishmen'tarianism, the main stress falls on -ta- and the weaker stresses, all marked ‘,’, are of different strength. English is said to be a stress language: every (lexical) word – noun, verb, adjective or adverb – has a stressed syllable, and where more than one syllable bears stress (as in some of the examples given above), one of these stresses will be the main stress, and the others subordinated.

In phonetic terms, stressed syllables in English are produced with a stronger burst in initiatory energy – a more powerful contraction of the chest muscles – than unstressed syllables are. (Recall here, for comparison, the phonetics of the syllable discussed in sect. 6.2 above.) On the acoustic side, this increased energy input results in greater loudness, increased duration and often – mainly in the case of primary stress – a change of pitch.