Speech rhythm (source code)

= Speech rhythm

<Speech rhythm> is the temporal organization of <speech>: the durations and grouping of segments, <syllables>, pauses and prominent portions of an utterance. It is one component of <prosody>, distinct from the changing <pitch> pattern of <speech intonation>.

An original measurement exercise is to record several repetitions of a short phrase at a comfortable rate, then again more quickly. Mark the same chosen boundaries on each recording and compare the elapsed times between them. Normalizing an interval by the utterance's total duration distinguishes uniform speeding-up from redistribution of time within the phrase. The result depends on which boundaries were marked, so the annotation rule is part of the measurement method. Software such as <Praat> stores labelled time intervals in separate annotation tiers, allowing the audio and its proposed segmentation to be inspected together.<Annotation in the Praat Manual by Paul Boersma>[Creating a TextGrid; View and edit: separate sound and annotation objects, interval tiers and editable boundaries]{ref}

Perceived rhythmic prominence is not simply the height of the <sound pressure> waveform. Duration, <pitch> and intensity can contribute differently, and a claim about regular timing requires measured intervals rather than an impression of a beat.