Quantitative Stress

an emphasis on the stressed elements of a word or phrase by means of an increase in their relative duration; as a rule, the stress arises from the interaction of several components. There are no known languages in which stress would be purely quantitative; it can only be affirmed that in some languages the stress is mostly quantitative—for example, in Russian, where a stressed syllable (and especially the vowel in it) has a greater relative duration than an unstressed syllable.