Acoustic characteristics of tense-lax vowel contrast in German: a pilot study of Hanover pronunciation of Standard German

It is well known that the tense and lax vowel contrast in German are accompanied by effects on vowel duration and (mainly the first and second) vowel formant frequencies (F1 and F2): generally, tense vowels have longer duration and more peripheral configurations in the F1 and F2 vowel space. The Northern pronunciation of Standard German vowels is widely thought to most closely reflect the standard acoustic realization of the tense and lax contrast. However, a cross-dataset comparison of previous studies on Northern German vowels shows that the formant (or spectral), rather than temporal, patterns differ in several respects, suggesting within-region variability. Building on these considerations, the present study investigated vowel duration, F1 (vowel height), and F2 (vowel backness) of the tense and lax vowel system in Hanover Standard German. Two female monolingual speakers from the Hanover region performed a reading task with 66 German words, each containing a stressed monophthong. The results showed that tense and lax vowels were consistently discriminated by vowel duration, whereas within each category, no coherent variation was observed. In contrast, the spectral cues seemed to be closely related to specific vowel categories. The tense vowels exhibited an unusual F1 raising, particularly in the front vowels /iː yː ɛː/, while lax vowels showed an F2 shift toward the vowel space center, most notably in the front and back vowels /ɪ ɛ ʊ ɔ/. These findings provide preliminary insight into the regional-specific acoustic properties in the Hanover vowel system, especially in comparison with the broader patterns of Northern German vowels.