Date of Award

Spring 1-1-2018

Document Type


Degree Name

Doctor of Philosophy (PhD)

First Advisor

Rebecca A. Scarborough

Second Advisor

Bhuvana Narasimhan

Third Advisor

Mans Hulden

Fourth Advisor

Esther Brown

Fifth Advisor

Didier Demolin


Vowel nasality is the most controversial phonological aspect of Brazilian Portuguese. Scholars suggest the oral-nasal vowel distinction may not exist. A consonant-like nasal resonance presence at the vowel’s right edge (the nasal appendix) might make nasal vowels the product of a contextual vowel nasalization rule. Others suggest that the appendix is a byproduct of a velum lowering gesture misalignment, so, nasal vowels are distinctive due to vowel-inherent differences in nasality and quality. Since two opposing conclusions can be reached by examining nasal vowels production, we seek a new source of evidence in listeners’ perception of these vowels.

This dissertation examines how Brazilian Portuguese listeners perceive vowel nasality, to shed light on the phonological status issue. The production study measured oral, nasal and nasalized vowels formants, and acoustic nasality to establish acoustic profiles. The rating perceptual experiment tested whether Brazilian Portuguese listeners treat potentially contrastive vowel nasality as a coarticulatory product of the appendix, i.e., perceptual compensation. The identification experiment tested whether they can identify a word based on vowel alone.

Results show that participants did not perceptually compensate for vowel nasality and identified words based solely on vowels. However, accuracy was much lower than expected. Two factors played a role in accuracy: vowel quality and appendix presence. Accuracy was higher when vowels were different in terms of vowel quality, as attested by differences in the production study; nasal answers increased when vowels were followed by the appendix, regardless of nasality type. The oral-nasal vowel contrast in Brazilian Portuguese is considered mainly a vowel quality contrast, caused by change in quality due to oral-nasal resonance interactions in nasal vowels. The perceptual distinction is clear in the low and the mid-front vowels, where vowel production shows quality differences, but not in the mid-back or high vowels, where quality differences are small. The appendix increased nasality judgement; it is thought that at least some part of the contrast lies with it. We conclude that vowel nasality in Brazilian Portuguese is phonologized and some vowels are phonemic. However, we cannot say whether phonologization is still ongoing, or whether it is halted by the appendix.