The accurate specification and prediction of segmental durations in speech has attracted a large number of research publications over the years. Such publications may be divided into two types, those which attempt to catalogue the various statistical properties of durations  or describe observable duration trends in speech , and those which explicitly attempt to predict the duration of segments   . In recent years, many papers attempting to understand the reasoning behind particular segment durations have included language structure in their descriptions . The causes of variation in the duration of a segment are now seen as a consequence of higher linguistic structure rather than just close proximity contextual effects. This drive to non-linear phonological descriptions has occurred in part due to a lack of success in improving upon the traditional context sensitive segment duration rules as advocated most notably by Klatt .
Bibliographic reference. Breen, Andrew P. (1995): "A simple method of predicting the duration of syllables", In EUROSPEECH-1995, 595-598.