Prosodic unit

In linguistics, a prosodic unit, often called an intonation unit or intonational phrase, is a segment of speech that occurs with a single prosodic contour (pitch and rhythm contour). The abbreviation IU is used and therefore the full form is often found as intonation unit, despite the fact that technically it is a unit of prosody rather than intonation, which is only one element of prosody. In linguistics, a prosodic unit, often called an intonation unit or intonational phrase, is a segment of speech that occurs with a single prosodic contour (pitch and rhythm contour). The abbreviation IU is used and therefore the full form is often found as intonation unit, despite the fact that technically it is a unit of prosody rather than intonation, which is only one element of prosody. Prosodic units occur at a hierarchy of levels, from the metrical foot and phonological word to a complete utterance. However, the term is generally restricted to intermediate levels which do not have a dedicated terminology. Prosodic units do not generally correspond to syntactic units, such as phrases and clauses; it is thought that they reflect different aspects of how the brain processes speech, with prosodic units being generated through on-line interaction and processing, and with morphosyntactic units being more automated. Prosodic units are characterized by several phonetic cues, such as a coherent pitch contour. Breathing, both inhalation and exhalation, only occurs at the boundaries (pausa) between higher units. Several short contours may carry an additional overall gradual decline in pitch and slowing of tempo; this larger unit is termed a declination unit (DU). At the boundaries (pauses) between declination units, the pitch and tempo reset; for this reason the final one of the shorter internal contours is said to have final prosody, whereas the others are said to have continuing prosody. These two levels of the hierarchy may be schematized as follows: In English orthography, a continuing prosodic boundary may be marked with a comma (assuming the writer is using commas to represent prosody rather than grammatical structure), while final prosodic boundaries may be marked with a full stop (period). The International Phonetic Alphabet has symbols (single and double pipes) for 'minor' and 'major' prosodic breaks. Since there are more than two levels of prosodic units, the use of these symbols depends on the structure of the language and which information the transcriber is attempting to capture. Very often, each prosodic unit will be placed in a separate line of the transcription. Using the single and double pipes to mark continuing and final prosodic boundaries, we might have American English,