The duration of duplicated vowels when in first/last word-syllable in Chilean Spanish

This investigation studies the duration of Spanish vowels in Santiago de Chile, in isolation and in adjacent pairs, within different phonological contexts. We used sentences with the five vowels and six possible conditions (stressed, unstressed, stressed + stressed, stressed + unstressed, unstressed + stressed, unstressed + unstressed) in the same syllabic position within each sentence. We carried out forty recordings of native speakers of Chilean Spanish. Results show five different groups, with the longest duration occurring in the combination stressed vowel + stress vowel, and the shortest duration observed in single unstressed vowels. Combinations unstressed vowel + stressed vowel, as well as stressed vowel + unstressed vowel, behave as a single group. Analyses by vowel show that /u/ displays the longest duration when unstressed, while /a/ shows the shortest duration in the same condition and the longest duration when stressed.