ISCA Archive Interspeech 2023
ISCA Archive Interspeech 2023

Bulgarian Unstressed Vowel Reduction: Received Views vs Corpus Findings

Mitko Sabev, Bistra Andreeva, Christoph Gabriel, Jonas Gruenke

Bulgarian is often cited in phonological work for its vowel reduction, with the assumption that the six-vowel stressed inventory, /ɛ a ɔ i ɤ u/, shrinks to three unstressed contrastive vowels, /i ɤ u/, by virtue of /ɛ a ɔ/ raising and merging with /i ɤ u/. The literature in Bulgarian, on the other hand, maintains that /ɛ-i/ do not merge in Standard Bulgarian; that vowels are less reduced in immediately pretonic syllables than elsewhere; that unstressed high vowels are lowered, while nonhigh vowels are raised; and that /a-ɤ/ are more likely to merge than /ɔ-u/. These claims have been challenged in recent work, and we present a new investigation based on 11,615 vowel tokens from 140 speakers in the BulPhonC speech corpus. MANOVA and GLMM results provide clear evidence that there is no unstressed high-vowel lowering, no difference between pretonic vs other unstressed vowels, and that both unstressed /a-ɤ/ and /ɔ-u/ merge completely, while /ɛ-i/ remain spectrally distinct.