Production and perception of the low vowels in American English

Two vowel features are especially pivotal in defining contemporary U.S. dialects: The merger of the low back vowels and the variable realizations of the low front vowel. Several scholars (Bigham 2010, Gordon 2005, Labov, Ash and Boberg 2006) suggest a relationship between the low front and low back vowels such that /æ/ raising and subsequent fronting of /ɑ/ in the North inhibits the tendency toward low back merger. However, little work examines the robustness of this “structural linkage” or whether a similar relationship obtains across different regional varieties. Further, little work examines whether differences in production correlate with differences in regional perception patterns. Here, we compare the low vowel system across U.S. regional dialects and also consider interrelationships (i.e., correlations) between low vowel categories using data from eight fieldsites across the U.S. We then look at what these speakers’ perceptions of category shift between the low front and low back vowel tells us about this relationship in production. Our results suggest both that the regional vowel shifts create significantly divergent low vowel systems across regions but also that /æ/ and /ɑ/ indeed show a structural linkage across regions, while /æ/ and /ɔ/ and /ɑ/ and /ɔ/ show no such relationship.