Looking within events: Examining internal temporal structure with local relative rate

This paper describes a method for quantifying temporally local variation in the relative rates of speech signals, based on warping curves obtained from dynamic time warping. Although the use of dynamic time warping for signal alignment is well established in speech science, its use to estimate local rate variation is quite rare. Here we introduce an extension of the local relative rate method that supports the quantification of variability in local relative rate, both within and across a set of events. We show how measures of temporal variation derived from this analysis method can be used to characterize the internal temporal structure of events. In order to achieve this, we first provide an overview of the standard dynamic time warping algorithm. We then introduce the local relative rate measure and describe our extensions, applying them to an articulatory and acoustic dataset of consonant-vowel-consonant syllable productions.