There are various ways in which stress manifests itself in the speech stream, and these depend to some extent on which language is being spoken. Stressed syllables are often louderthan non-stressed syllables, and

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Word stress, or sometimes lexical stress, is the stress placed on a given syllable in a word. The position of word stress in a word may depend on certain general rules applicable in the language or dialectin question, but in other languages, it must be learned for each word,

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Prosodic stress, or sentence stress, refers to stress patterns that apply at a higher level than the individual word – namely within a prosodic unit. It may involve a certain natural stress pattern characteristic of a given language, but may also involve the placing of

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In many languages, such as Russian and English, vowel reduction may occur when a vowel changes from a stressed to an unstressed position. In English, unstressed vowels may reduce to

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Some languages, such as English, are said to be stress-timed languages; that is, stressed syllables appear at a roughly constant rate and non-stressed syllables are shortened to

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It is common for stressed and unstressed syllables to behave differently as a language evolves. For example, in the Romance languages,

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An operational definition of word stress may be provided by the stress "deafness" paradigm. The idea is that if listeners perform poorly on

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