Phonetic variation in voiced obstruents in North-Central Peninsular Spanish

In Spanish, /b, d, [vvplosive]/ are usually spirantized to voiced approximants in all syllabic contexts after a continuant sound. However, in North-Central Peninsular Spanish (NCS), spirantization interacts with coda devoicing, yielding voiceless fricatives. In the majority of cases, coda /b, d, [vvplosive]/ occur in stressed syllables. This work examines whether or not stress is a factor in the likelihood of frication and devoicing of coda /b, d, [vvplosive]/ in this dialect. An acoustic study was conducted of nine native speakers from NCS. These speakers were tested on nonce words with /b, d, [vvplosive]/ in coda position in both stressed and unstressed syllables. Measurements were made of vowel and consonant duration, presence and absence of frication and voicing, and voicing duration. The results show that frication is more likely in stressed syllables than in unstressed syllables. This suggests that in stressed syllables, a higher subglottal pressure produces higher airflow across the glottis, thereby favoring frication. In turn, frication inhibits voicing due to conflicting aerodynamic requirements between the two. We conclude that stress is a factor in spirantization and that it may indirectly affect the voicing properties of /b, d, [vvplosive]/.