This study investigated the ways in which segmental durations co-vary across speakers in a large speech corpus. We found that pauses were negatively correlated with other phones. Speakers who produced longer speech phones tended to have shorter pauses. The approximants had little correlation with the other phone classes. This suggests that the durations of the approximants are controlled by speaker-dependent mechanisms.
Bibliographic reference. Yuan, Jiahong (2008): "Covariations of English segmental durations across speakers", In INTERSPEECH-2008, 1963.