2.2 Factors that affect duration of segments and pauses Since oral reading involves saying the text aloud, the durations of individual segments, words and phrases as well as location and duration of silent pauses are subject to constraints that have been extensively studied in literature on phonetic timing; see White (2014); Hirschberg (2002) for a review.
it has been long known that different segments have different intrinsic durations which account for a lot of variation in segmental durations (Peterson and Lehiste, 1960;Klatt, 1976;van Santen, 1992): for example, high vowels tend to be shorter than low vowels.