Segmental and prosodic cues to vowel identification: The case of /I i i:/ and /U u u:/ in Saterland Frisian

Saterland Frisian has a complete set of closed short tense vowels. Together with the long tense vowels and the short lax vowels they constitute series of phonemes that differ by length and/or tenseness. We examined the cues that distinguish the front unrounded and the back rounded series of short lax and short and long tense vowels in triplets by eliciting ‘normal speech’ and ‘clear speech’ in a reading task from two speakers. Short and long vowels were distinguished by vowel duration, and lax and tense vowels by their location in the F1-F2 space. The durational difference between short tense and long tense vowels, however, was largely restricted to the ‘clear speech’ condition. In ‘clear speech’, f0 dynamics and centralization in the F1-F2 space were used as additional means to make short tense vowels more distinct from long tense vowels. These results suggest that length and tenseness are used as distinctive features, while f0 dynamics and centralization in the F1-F2 space were optionally used to enhance the contrast between short and long tense vowels. Index Terms: f0 dynamics, f0 excursion, formants, Saterland Frisian, tenseness, vowel duration