The Estonian Swedish diphthongs /ai au oi ui/: Acoustic characteristics and cross-dialectal variation

Sammanfattning: This study investigates the acoustic characteristics and cross-dialectal variation of the diphthongs /ai au oi ui/ in the Nuckö, Ormsö, and Rickul varieties of Estonian Swedish, which have previously only been described impressionistically (Lagman, 1979; Danell, 1905-34). Eight acoustic measures, reflecting the F1 and F2 frequency values at the first (InF1 and InF2) and second (FinF1 and FinF2) vowel targets, total diphthong duration, amount of spectral change (TL), and spectral rate of change (TLroc and VSLroc), were employed to analyze differences between diphthong categories within each dialect as well as differences in the realization of each diphthong category across dialects. The results, based on data from 498 diphthong tokens in 20 elderly speakers, indicate that the main realizations of /ai oi ui/ are cross-dialectally stable as [a͡ɪ]~[a͡e], [o͡ɪ]~[ɔ͡ɪ], and [u͡i] in all three dialects with major distinctions between diphthong categories found in the InF1, InF2, FinF1, and TLroc measures. In contrast, the results for /au/ indicate considerable cross-dialectal variation with the main realizations [a͡u̞]~[a͡ʉ], [œ͡ʏ], and [a͡u̞] in the Nuckö, Ormsö, and Rickul dialects respectively, which is reflected as variation in the height of the first target (InF1), the backness of the second target (FinF2), and the amount of spectral change (TL). Additionally, substantial intra-dialectal variation was also observed in the second target of Nuckö /au/ and in the first target of Ormsö /au/. Thus, for the first time, the current study provides acoustic evidence that confirms many of the observations featured in earlier impressionistic descriptions (Lagman, 1979; Danell, 1905-34) on the characteristics and cross-dialectal variation of the Estonian Swedish diphthongs /ai au oi ui/.