Volume 6, Issue s1 - Special Issue: Innovative Methods in Sociophonetics / Issue Editors: Nicolai Pharao and Anne H. Fabricius

This paper considers the relative influence on sociophonetic interpretation of /s/ using “static” and “dynamic” acoustic analysis, where dynamic refers to the use of measures which capture the time-varying nature of segmental acoustics, and static to measures which are taken at a single point, or from an average across the sound (Watson and Harrington 1999, Docherty et al. 2015). Static and dynamic Discrete Cosine Transformation (DCT) analyses of spectral Centre of Gravity (CoG) and spectral Slope measures/trajectories were carried out on gendered productions of /s/ and /ʃ/ for a real- and apparent-time 32 speaker sample of spontaneous Glasgow dialect. Results of static CoG measures, reflecting place of articulation, indicate a reduction of gender differentation over time, such that girls born most recently revert to older vernacular (lower frequency) norms. Adding static spectral Slope, reflecting articulatory constriction, shows a change in gendered differentiation, whereby boys born most recently show a gestural shift. The DCT analysis both confirms the static results and also reveals that dynamic characteristics of both sibilants carry key additional prosodic, linguistic and social information for this community. Our results reflect for the first time the usefulness of changing analytical perspectives on /s/, both in terms of acoustic representation (static and dynamic), but also by considering /s/ alongside its partner sibilant /ʃ/ within the context of shifts in the construction of social gender over time.

Forensic speech science is the application of speech analysis methods to forensic recordings; in many jurisdictions this is predominantly the application of sociophonetics. Sociophonetics and forensic speech science have developed as independent research areas with their own aims, methodologies and identities, and the gap between the fields has arguably grown bigger in recent years. Yet, there is much to be gained for both fields from closer collaboration through sharing methods, data, and knowledge. We will argue that this is more important now given the increasing demands on forensic science to more rigorously and empirically test and validate methods, and current trends in sociophonetics towards understanding how different linguistic variables are used by speakers to enact different identities in different situations. In this paper, we review the relationship between sociophonetics and forensic speech science. We also outline how developments in both fields can, and do, directly contribute to improving the quality of forensic voice evidence, as well as informing theoretical and practical aspects of sociophonetics.

Sociolinguistic data collection traditionally includes interviews, reading passages, and word lists (Labov 1972). Researchers have increasingly sought out elicitation tasks that have the benefits of tasks based on reading aloud (e.g., studying infrequently occurring variables; controlling for linguistic factors; eliciting the same lexical items across participants) while also eliciting styles more comparable to interview speech (see Drager 2018). Examples include the Map Task (Brown et al. 1984) and the Diapix task (Baker and Hazan 2011). Other researchers have turned instead to elicitation tasks that maximize ecological validity, taking themselves out of the recording context and training participants to collect field recordings (e.g., Podesva 2007; Sharma 2011). But how comparable is the speech elicited from each of these tasks? Building on results from previous research (Boyd et al. 2015; Hall-Lew and Boyd 2017) we consider three US English speakers’ vowel productions from interviews, reading passages, ‘Lab Tasks’, and self-recordings. We suggest that both Lab Tasks and self-recordings have the potential to increase descriptive accuracy and indexical analysis in sociophonetic research.

This paper presents an analysis of the performance and usability of automatic speech processing tools on six different varieties of English spoken in the British Isles. The tools used in the present study were developed for use with Mainstream American English, but we demonstrate that their forced alignment functionality nonetheless performs extremely well on a range of British varieties, encompassing both careful and casual speech. Where phone boundary placement is concerned, substantial errors in alignment occur infrequently, and although small displacements between aligner-placed and human-placed phone boundaries are found regularly, these will rarely have a significant effect on measurements of interest for the researcher. We demonstrate that gross phone boundary placement errors, when they do arise, are particularly likely to be introduced in fast speech or with varieties that are radically different from Mainstream American English (e.g. Scots). We also observe occasional problems with phonetic transcription. Overall, we advise that, although forced alignment software is highly reliable and improving continuously, human confirmation is needed to correct errors which can displace entire stretches of speech. Nevertheless, sociolinguists can be assured that the output of these tools is generally highly accurate for a wide range of varieties.

This paper contributes insight into the sources of variability in vowel formant estimation, a major analytic activity in sociophonetics, by reviewing the outcomes of two simulations that manipulated the settings used for linear predictive coding (LPC)-based vowel formant estimation. Simulation 1 explores the range of frequency differences obtained when minor adjustments are made to LPC settings, and measurement timepoints around the settings used by trained analysts, in order to determine the range of variability that should be expected in sociophonetic vowel studies. Simulation 2 examines the variability that emerges when LPC settings are varied combinatorially around constant default settings, rather than settings set by trained analysts. The impacts of different LPC settings are discussed as a way of demonstrating the inherent properties of LPC-based formant estimation. This work suggests that differences more fine-grained than about 10 Hz in F1 and 15–20 Hz in F2 are within the range of LPC-based formant estimation variability.

Regional varieties of Danish are distinguished mainly by prosodic cues, in particular the tonal stress group pattern. We test the hypothesis that prosody is a strong cue for identifying the regional background of speakers. This hypothesis was studied using an online survey in which listeners were asked to identify the origin of speakers based on examples from four different regional varieties of Danish. Listeners identified speaker origin on the basis of both natural, monotonised and delexicalised speech samples. The results show that although most listeners are able to identify the four regional varieties correctly, it is more reasonable to say that Danes categorise the regional varieties into broader categories of Western and Eastern Danish. Prosody clearly plays an important role in the identification of the varieties, but reliable identification is difficult based on prosody alone.