Distance vs time. Acoustic and articulatory consequences of reduced vowel duration in Polish.

This paper presents acoustic and articulatory (ultrasound) data on vowel reduction in Polish. The analysis focuses on the question of whether the change in formant value in unstressed vowels can be explained by duration-driven undershoot alone or whether there is also evidence for additional stress-specific articulatory mechanisms that systematically affect vowel formants. On top of the expected durational differences between the stressed and unstressed conditions, the duration is manipulated by inducing changes in the speech rate. The observed vowel formants are compared to expected formants derived from the articulatory midsagittal tongue data in different conditions. The results show that the acoustic vowel space is reduced in size and raised in unstressed vowels compared to stressed vowels. Most of the spectral reduction can be explained by reduced vowel duration, but there is also an additional systematic effect of F1-lowering in unstressed non-high vowels that does not follow from tongue movement. The proposed interpretation is that spectral vowel reduction in Polish behaves largely as predicted by the undershoot model of vowel reduction, but the effect of undershoot is enhanced for low unstressed vowels, potentially by a stress marking strategy which involves raising the fundamental frequency.

Fronting of Southern British English high-back vowels in articulation and acoustics.

The fronting of the two high-back vowels /uː/ and /ʊ/ in Southern British English is very well documented, but mainly in the acoustic domain. This paper presents articulatory (ultrasound) data, comparing the relative tongue position of these vowels in fronting and non-fronting consonantal contexts, i.e., preceding a coronal consonant (food, foot) and preceding a coda /l/ (fool, full). Particular attention is paid to the comparison between articulatory results and corresponding acoustic measurements of F2 in both vowels. Results show that the average differences between food and foot and their dynamic profiles are similar in articulation and acoustics. In /uːl/ sequences (fool), tongue position is more advanced than could be inferred from its low F2. In addition, even though the tongue position in fool and full is clearly distinct, there is no comparable corresponding difference in F2. This suggests that the common articulatory metaphor that characterises F2 increase as fronting must be used cautiously. In the case of English high-back vowel fronting, special attention must be paid to the flanking consonants when estimating vowel distances. This paper also provides specific recommendations for recording and analysing ultrasound data in research on vowel variation and change.

General Northern English. Exploring Regional Variation in the North of England With Machine Learning.

In this paper, we present a novel computational approach to the analysis of accent variation. The case study is dialect leveling in the North of England, manifested as reduction of accent variation across the North and emergence of General Northern English (GNE), a pan-regional standard accent associated with middle-class speakers. We investigated this instance of dialect leveling using random forest classification, with audio data from a crowd-sourced corpus of 105 urban, mostly highly-educated speakers from five northern UK cities: Leeds, Liverpool, Manchester, Newcastle upon Tyne, and Sheffield. We trained random forest models to identify individual northern cities from a sample of other northern accents, based on first two formant measurements of full vowel systems. We tested the models using unseen data. We relied on undersampling, bagging (bootstrap aggregation) and leave-one-out cross-validation to address some challenges associated with the data set, such as unbalanced data and relatively small sample size. The accuracy of classification provides us with a measure of relative similarity between different pairs of cities, while calculating conditional feature importance allows us to identify which input features (which vowels and which formants) have the largest influence in the prediction. We do find a considerable degree of leveling, especially between Manchester, Leeds and Sheffield, although some differences persist. The features that contribute to these differences most systematically are typically not the ones discussed in previous dialect descriptions. We propose that the most systematic regional features are also not salient, and as such, they serve as sociolinguistic regional indicators. We supplement the random forest results with a more traditional variationist description of by-city vowel systems, and we use both sources of evidence to inform a description of the vowels of General Northern English.