Algherese Catalan has the peculiarity of presenting an inserted [i] vowel across words in order to avoid certain consonant codas. In this study, we compare five acoustic features of this epenthetic segment (i.e., duration, intensity, and the three first formants) with those of lexical /i/ vowels, both stressed and unstressed. The results indicate that the three vowels present differences only with respect to duration, F2 and, to a lesser extent, F3. The second formant values decline progressively from the lexical stressed vowels to the inserted unstressed segments, with lexical unstressed segments at an intermediate point. This gradation mirrors the relative prominence of each vowel. The differences in F2 between lexical stressed and unstressed vowels can be attributed to the shorter duration of the later segments. Lexical unstressed and inserted vowels, however, have an equivalent duration, challenging the idea that inserted vowels are more centralized due to their shorter duration. All in all, the data point to a double contrast: first, between lexical stressed and unstressed segments and, second, between unstressed segments.