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.