TY - JOUR

T1 - Articulation Rates' Inter-Correlations And Discriminating Powers In An English Speech Corpus

AU - Plug, Leendert

AU - Lennon, Robert

AU - Gold, Erica

N1 - This is the author’s version of a work that was accepted for publication in Speech Communication. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Speech Communication, 132, 2021 DOI: 10.1016/j.specom.2021.05.006

PY - 2021/9/30

Y1 - 2021/9/30

N2 - Studies that quantify speech tempo on acoustic grounds typically use one of various rate measures. The availability of multiple measurement techniques yields ‘researcher degrees of freedom’ which call the robustness of generalisations across studies into question. However, explicit assessments of the possible impact of researchers’ choices among the available measures are rare. In this study we attempt such an assessment by comparing the distributions of five common rate measures―canonical and surface syllable and phone rates, and CV segment rate―calculated over fluent stretches of unscripted speech produced by 100 English speakers. We assess the measures’ inter-correlations across the corpus as a whole as well as in relevant data samples to simulate multiple analysis scenarios. We also report on deletion rates in our corpus, as they determine the relationship between canonical and surface rates; we assess the impact on rate figures of variable assumptions as to what constitutes deletion; and we compare the measures’ discriminating powers in a forensic analysis context using Bayesian likelihood ratios. Our results suggest that in a sizeable English corpus with normal deletion rates, the five rates are closely inter-correlated and have similar discriminating powers; decisions as to the segmental make-up of canonical forms also have limited impact on distributions. Therefore, for common analytical purposes and forensic applications the choice between these measures is unlikely to substantially affect outcomes.

AB - Studies that quantify speech tempo on acoustic grounds typically use one of various rate measures. The availability of multiple measurement techniques yields ‘researcher degrees of freedom’ which call the robustness of generalisations across studies into question. However, explicit assessments of the possible impact of researchers’ choices among the available measures are rare. In this study we attempt such an assessment by comparing the distributions of five common rate measures―canonical and surface syllable and phone rates, and CV segment rate―calculated over fluent stretches of unscripted speech produced by 100 English speakers. We assess the measures’ inter-correlations across the corpus as a whole as well as in relevant data samples to simulate multiple analysis scenarios. We also report on deletion rates in our corpus, as they determine the relationship between canonical and surface rates; we assess the impact on rate figures of variable assumptions as to what constitutes deletion; and we compare the measures’ discriminating powers in a forensic analysis context using Bayesian likelihood ratios. Our results suggest that in a sizeable English corpus with normal deletion rates, the five rates are closely inter-correlated and have similar discriminating powers; decisions as to the segmental make-up of canonical forms also have limited impact on distributions. Therefore, for common analytical purposes and forensic applications the choice between these measures is unlikely to substantially affect outcomes.

KW - articulation rate

KW - speaker comparison

KW - correlations

U2 - 10.1016/j.specom.2021.05.006

DO - 10.1016/j.specom.2021.05.006

M3 - Journal article

VL - 132

SP - 40

EP - 54

JO - Speech Communication

JF - Speech Communication

SN - 0167-6393

ER -