Dialect variation in formant dynamics: The acoustics of lateral and vowel sequences in Manchester and Liverpool English

Abstract

literature. Jones (1966, 92) speculates that Liverpool /l/ may be clear in all positions, 61 stating that 'its existence there is probably due to Irish influence', with many varieties of 62 Irish English having very clear /l/s. Knowles (1973, 256) claims that /l/ in Liverpool is 63 frequently 'velarised' and produced in similar ways across positions. One of the few sources 64 of instrumental data on Liverpool /l/ comes from Turton (2014), who reports acoustic 65 and ultrasound data on a single male speaker. She finds that he produces the initial∼final 66 contrast in /l/, but that he also produces word-final /l/ with distinct velarisation, as opposed 67 to the more pharyngealised articulations documented for other British English varieties. This 68 also suggests a potentially 'intermediate' realization for Liverpool /l/, which may lie towards 69 the middle of a continuum between clear and dark. 70In this study, we address the relationship between time-varying lateral and vowel formant 71 dynamics. Accordingly, we briefly overview previous research on vowels in each variety. 72Manchester English shows features typical of many northern Englishes, such as the lack of a 73 foot-strut or trap-bath split and monophthongal productions of canonical diphthongs 74 (Baranowski and Turton, 2015). Liverpool English typically merges the nurse and square 75 vowels (Knowles, 1973; Watson, 2007) and has complex patterns of raising in price and 76 mouth before nasal-obstruent clusters (Cardoso, 2015). 77A concrete difference between dialects that we predict will have an effect on our results is 78 the final vowel in words such as belly (Wells 1982 calls this the happy vowel). Manchester is 79 reported to produce very low and back variants of happy (Baranowski and Turton, 2015), 80 which we do not expect to see in Liverpool. Finally, we discuss pre-lateral vowels, which are 81 5 Dialect variation in formant dynamics particularly significant for our study. Fronting of /u/ is typically inhibited before coda /l/ in 82 some varieties of English (Kleber et al., 2011), although the articulatory interpretation of this 83 is not straightforward (Strycharczuk and Scobbie, 2017). However, Baranowski (2017) finds 84 a clear social class effect on pre-lateral /u/ fronting in Manchester, with a strong negative 85 correlation between social class and fronting in this context. While we are not aware of any 86 studies of pre-lateral /u/ in Liverpool, our own impressions suggest that fronting of /u/ 87 before coda /l/ is widespread in this dialect. 88 B. Time-varying spectral analysis 89 The significance of the time-varying properties of sonorant sounds has been comprehen-90 sively documented in the literature (Elvin et al., 2016; Fox and Jacewicz, 2009; Strycharczuk 91 and Scobbie, 2017; Watson and Harrington, 1999; Williams and Escudero, 2014). This is 92 particularly pertinent to a study of laterals, which are inherently non-static due to the tim-93 ing relations outlined in Section I A, as well as the existence of strong interactions be...

Acquiring allophonic structure and phonetic detail in a bilingual community: The production of laterals by Sylheti-English bilingual children

“…Segmentation of the acoustic signal was conducted manually using visual observation of the waveform and wide-band spectrogram. The lateral and its adjacent vowels were segmented according to published criteria in the literature (Carter & Local, 2007;Kirkham, 2017;Kirkham et al, 2019). Specifically, the lateral phase was defined as a period during which F2 was steady or as close to steady as possible, representing an unambiguously lateral sound.…”

“…Optimal LPC settings were empirically determined for each speaker using a method similar to Escudero et al (2009). We focus on the measure of F2-F1 because previous research shows this to be an effective measure of lateral quality (Kirkham et al, 2019;Sproat & Fujimura, 1993). Formant values were then converted to z-scores to better facilitate speaker comparison, especially as our primary focus is on within-speaker contrasts between different word positions.…”

Dynamic acoustic-articulatory relations in back vowel fronting: Examining the effects of coda consonants in two dialects of British English

“…We extracted measurements from the EMA data at 10% intervals between the acousticallydefined onset and offset of each vowel or vowel-lateral interval, which represent the same time-points as for the formant data. In the case of pre-lateral vowels, the lateral was included in the interval for both the articulatory and formant data due to the difficulty of identifying consistent segmental boundaries (Kirkham et al, 2019;Strycharczuk and Scobbie, 2017).…”

“…This difference is inevitable, given the difficulties of reliable segmentation between vowels and laterals, which is particularly evident in the case of coda laterals. Indeed, much previous research has taken a similar approach, analysing the dynamics of the vowel-lateral interval as an entire syllable unit (Carter and Local, 2007;Kirkham, 2017;Kirkham et al, 2019;Nance, 2014).…”

Analyzing speech in both time and space: Generalized additive mixed models can uncover systematic patterns of variation in vocal tract shape in real-time MRI

“…Generalized additive mixed models (GAMMs; Wood, 2004Wood, , 2006a are an extension of GAMs as mixed models, in which random effects are estimated from a GAM by computing the variances of the so-called 'wiggly' components of the smooth terms (i.e., the degree of smoothness of the terms). GAMMs have previously been used to investigate speech production over time (Baayen, Vasishth, Kliegl, & Bates, 2017;Kirkham, Nance, Littlewood, Lightfoot, & Groarke, 2019;Mielke, Carignan, & Thomas, 2017;Sóskuthy, 2017;Wieling et al, 2016;Winter & Wieling, 2016) and space (Barlaz et al, 2018;Wieling, 2018), to observe the effects of word frequency and lexical proficiency on articulation (Tomaschek, Tucker, Fasiolo, & Baayen, 2018), and to model spatio-temporal relations in flesh-point kinematics (Tomaschek, Arnold, Bröker, & Baayen, 2018). One distinct advantage of employing GAMMs for speech articulation research is that they can capture the interaction effects of two different continuous variables (such as time and space), using tensor product interaction, which allows the smooth coefficients for one variable to vary in a non-linear fashion depending on the value of the other variable (Wieling, 2018, p. 102).…”