Length contrast and contextual modifications of duration in the Lithuanian vowel system
Previous studies have shown that the system of contrasts in a given language plays a significant role in determining certain contextual modifications stemming from coarticulation or the acoustic realization of stress. They argue that a limit on coarticulation occurs in cases where a high degree of coarticulation and its corresponding acoustic consequences would decrease the saliency of the relevant contrast. The current study investigates the role of contrastive vowel length in limiting the amount of contextual modification of vowel duration. More precisely, the interaction between vowel length contrast and the stop voicing effect is analyzed. The stop voicing effect results in vowel duration differences depending on whether the following obstruent is voiced or voiceless. The hypothesis is that the presence of vowel length contrast will inhibit the voicing effect, given that contextual variability of duration might blur a contrast based on length. This prediction is tested on Lithuanian, which has an asymmetrical vowel length system: only high and low vowels are contrastive for this dimension; mid vowels are always long. The experimental results show that the voicing effect is stronger for mid vowels, supporting the hypothesis that the presence of a length contrast attenuates the contextual effects on vowel duration.
Keywords: phonological contrast, vowel duration, voicing effect, Lithuanian