Acoustic realizations of a given phonetic segment are typically affected by coarticulation with the preceding and following phonetic context. While coarticulation has been extensively studied using descriptive phonetic measurements, little is known about the functional impact of coarticulation for speech processing. Here, we use DTW-based similarity defined on raw acoustic features and ABX scores to derive a measure of the effect of coarticulation on phonetic discriminability. This measure does not rely on defining segment-specific phonetic cues (formants, duration, etc.) and can be applied systematically and automatically to any segment in large scale corpora. We illustrate our method using stimuli in English and Japanese. We confirm some expected trends, i.e., stronger anticipatory than perseveratory coarticulation and stronger coarticulation for lax/short vowels than for tense/long vowels. We then quantify for the first time the impact of coarticulation across different segment types (like vowels and consonants). We discuss how our metric and its possible extensions can help addressing current challenges in the systematic study of coarticulation.
Cite as: Schatz, T., Turnbull, R., Bach, F., Dupoux, E. (2017) A Quantitative Measure of the Impact of Coarticulation on Phone Discriminability. Proc. Interspeech 2017, 3033-3037, doi: 10.21437/Interspeech.2017-1306
@inproceedings{schatz17_interspeech,
author={Thomas Schatz and Rory Turnbull and Francis Bach and Emmanuel Dupoux},
title={{A Quantitative Measure of the Impact of Coarticulation on Phone Discriminability}},
year=2017,
booktitle={Proc. Interspeech 2017},
pages={3033--3037},
doi={10.21437/Interspeech.2017-1306}
}