The combination of the retraction of TRAP and the merger of LOT and THOUGHT can be found in a number of English dialects. Gordon (2005) has suggested that the merger of LOT and THOUGHT creates a margin of security in which TRAP may retract, and that TRAP-retraction might therefore be expected to be found anywhere the low-back vowel merger exists. This work presents data showing the combination of these two kinds of vowel variation among emerging adult speakers in Illinois. F1 and F2 were measured for TRAP, LOT, and THOUGHT tokens taken from word list recitation and interview speech data for 26 emerging adult speakers from Southern Illinois, Chicagoland, and I-55 Corridor. The data clearly show that speakers in Southern Illinois engage in forms of both TRAP-retraction and the low-back vowel merger. While finding the low-back vowel merger in a South Midland U.S. dialect is unsurprising, the discovery of a well backed TRAP vowel (often further back than the F2 grand mean) in this region is novel. By interpreting the position of TRAP as a function of the degree of low-back vowel merger (i.e., always merged, occasionally merged, or always distinct), we see that Gordon’s suggestion is borne out at the community level. However, the functionalist argument underlying Gordon’s suggestion (i.e., that the retraction of TRAP follows as a result of the “vacuum” in vowel space created by the low-back vowel merger) is not entirely upheld. Though TRAP-retraction and the low-back vowel merger are linked at the community level, at the level of individual speakers this correlation breaks down. It is suggested that this disjoint can be resolved by viewing these results through a model of linguistic variation based on principles of evolution and emergence.
Bigham, Douglas S.
"Correlation of the Low-Back Vowel Merger and TRAP-Retraction,"
University of Pennsylvania Working Papers in Linguistics: Vol. 15
, Article 4.
Available at: http://repository.upenn.edu/pwpl/vol15/iss2/4