Vowels LOT, CLOTH AND THOUGHT
There was a major split within New England as early as the 1930s at which point ENE did not have a distinction between LOT and THOUGHT, while WNE had two distinct phonemes, (Kurath 1939-43, discussed in Boberg (2001: 13). ENE pronounced both LOT- and THOUGHT-type words with 
, while virtually all of WNE used [a] and 
respectively, resembling NYC.
One modern exception to this pattern is Providence, RI, where the two vowels are distinct (Labov 2000: Map 1). Another may be Calais, ME, where no speakers reported a merger in Miller (1989: 101). More recent data (Labov, Ash and Boberg fc.) presents a strikingly different picture for the LOT/THOUGHT merger. While all western CT speakers keep the two values clearly distinct, resembling the Inland North pattern, seven of eight VT speakers have completely merged the two vowels. One older northern VT woman did not merge these vowels, suggesting that the merger is more recent in VT than CT (Boberg 2001: 20). This trend is supported by unpublished data from the McGill-Vermont-New Hampshire Survey (Nagy, Roberts and Boberg 2002) which shows most New England speakers report merging these two vowels. Our two recorded NH speakers produced LOT, CLOTH and THOUGHT with [a]. One of them also produced PALM with this vowel.
Boberg (2001: 22) attributes the presence of the merger in VT to lack of contact with the Inland North (due to the barrier of Lake Champlain) combined with contact over the Green Mountains with the merged speakers of NH. In contrast, CT speakers have more contact with NY and thus retain the distinction. Geographically located between CT and VT, western MA speakers exhibit an intermediary variable pattern. In our data, however, MA has the highest rate of merger. Interestingly, Burlington, VT speakers show a tendency to merge LOT and THOUGHT in low back position, similar to the ENE merger (and to the Canadian merger just north of them), whereas the two Rutland speakers, 67 miles south, show a merger in low-central position (like that of southwestern NE) (Boberg 2001: 24), providing a gradual transition between the northern and southern WNE patterns.
To summarize, with respect to the LOT/THOUGHT merger and BATH/TRAP/ DANCE raising, ENE has full merger of LOT/THOUGHT (except RI) and no BATH/ TRAP/DANCE raising, except for that reported in Boston by Laferriere (1977). WNE is more complex:
The CT portion of the lower Connecticut Valley (the Hartford area) is a pure Northern [NCCS] system, with raised [bath/trap] and centralized [lot], distinct from mid-back [thought]. Northwestern VT (Burlington) is a pure “third dialect” system, not unlike the Canadian systems to the north of it [with no bath raising and a lot/thought merger]. Between Burlington and the lower Connecticut Valley are two transitional types. Springfield, and perhaps western MA in general, is basically Northern [NCSS] but shows a reduction of contrast between the low-back vowels, which may be tending toward merger among the youngest speakers in that area. Southwestern VT (Rutland) shows a solid merger of the low-back vowels but in the phonetic position characteristic of [lot] in western MA and CT (Boberg 2001:25-6).
