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This study considers the role of different cognitive units in sound change: phonemes, contextual variants and words. We examine /u/-fronting and /j/-dropping in data from three generations of Derby English speakers. We analyze dynamic formant data and auditory judgments, using mixed effects regression methods, including generalized additive mixed models (GAMMs). /u/-fronting is reaching its end-point, showing complex conditioning by context and a frequency effect that weakens over time. /j/-dropping is declining, with low-frequency words showing more innovative variants with /j/ than high-frequency words. The two processes interact: words with variable /j/-dropping (new) exhibit more fronting than words that never have /j/ (noodle) even when the /j/ is deleted. These results support models of change that rely on phonetically detailed representations for both word- and sound-level cognitive units., (© 2018 Cognitive Science Society, Inc.)

Across forensic speech science, the likelihood ratio (LR) is increasingly becoming accepted as the logically and legally correct framework for the expression of expert conclusions. However, there remain a number of theoretical and practical shortcomings in the procedures applied for computing LRs based on speech evidence. In this paper we review how the LR is currently applied to speaker comparison evidence and outline three specific areas which deserve further investigation: namely statistical modelling, issues relating to the relevant population and the combination of LRs from correlated parameters. We then consider future directions for confronting these issues and discuss the implications for forensic comparison evidence more generally., (Copyright © 2014 Forensic Science Society. Published by Elsevier Ireland Ltd. All rights reserved.)

Among phoneticians, the Vocal Profile Analysis (VPA) is one of the most widely used methods for the componential assessment of voice quality. Whether the ultimate goal of the VPA evaluation is the comparative description of languages or the characterization of an individual speaker, the VPA protocol shows great potential for different research areas of speech communication. However, its use is not without practical difficulties. Despite these, methodological studies aimed at explaining where, when and why issues arise during the perceptual assessment process are rare. In this paper we describe the methodological stages through which three analysts evaluated the voices of 99 Standard Southern British English male speakers, rated their voices using the VPA scheme, discussed inter-rater disagreements, and eventually produced an agreed version of VPA scores. These scores were then used to assess correlations between settings. We show that it is possible to reach a good degree of inter-rater agreement, provided that several calibration and training sessions are conducted. We further conclude that the perceptual assessment of voice quality using the VPA scheme is an essential tool in fields such as forensic phonetics but, foremost, that it can be adapted and modified to a range of research areas, and not necessarily limited to the evaluation of pathological voices in clinical settings. [ABSTRACT FROM AUTHOR]

There is now abundant evidence that phonetic forms are shaped by probabilistic effects reflecting predictability or informativity. We outline a number of challenges for such work, where theoretical claims are often based on small differences in acoustic measurements, or interpretations of small statistical effect sizes. We outline caveats about the methods and assumptions encountered in many studies of predictability effects, particularly regarding corpus-based approaches. We consider the wide range of factors that influence patterns of variability in phonetic forms, taking a broad perspective on what is meant by "the message" in order to show that predictability effects need to be considered alongside many others, including indexical and prosodic factors. We suggest a number of ways forward to extend our understanding of the form-predictability relationship. [ABSTRACT FROM AUTHOR]

This study assesses the extent to which likelihood ratios (LRs) are affected by analyst decisions regarding the number of reference speakers, number of tokens per speaker, and degree of linguistic match between the suspect-offender and the reference data. Using F1 and F2 trajectories from spontaneous /u:/ vowels, LRs were computed against a reference set of up to 120 speakers, and between 2 and 13 tokens per speaker. LR scores proved robust when using more than 30 speakers, although validity improved as sample size increased. Regional dialect mismatch produced stronger same-speaker scores by an average of one log10 order of magnitude. Validity (EER and Cllr) was also generally poorer in the dialect mismatch conditions. The results indicate that small amounts of reference data should generally be avoided, and that an awareness of the complexity of sociophonetic variation is essential in the definition of the relevant population for voice comparison. [ABSTRACT FROM AUTHOR]