At the time of the Linguistic Atlas of New England (LANE) fieldwork, both BATH and TRAP comprised a unified low front vowel across New England (Kurath 1939– 43: Maps 150 sack, 344 pantry, and 371 dad, cited in Boberg 2001: 13). Laferriere’s (1977: 102–3) findings from urban Boston show a less uniform picture. She reported for BATH a non-productive backing: lexicalized and categorical before many /f/ and /θ/ words and in some /n/ words (e.g., half, rather, aunt) and lexicalized but variable before /s/ and in other /n/ words (e.g., last, dance). Supporting evidence comes from Calais, ME, where a majority of speakers report saying [ant] for aunt. Some speakers report [ant], but none report [ænt]. This differs from much of the US, where [ænt] is used (Miller 1989: 124). Our NH speakers use [æ] for all of these word classes except aunt, which is [a].

Laferriere (1977) also reports a productive, phonological process raising TRAP and BATH to [εə​], demonstrated by her younger speakers. As this process was found to affect both TRAP and BATH vowels, it thus encroaches on the lexical BATH class that had been subjected to backing. A more recent study of WNE found raising of the nucleus in TRAP and BATH in all environments and tensing (as well as raising) before nasals (DANCE) (Boberg 2001: 17–19). A small sample of telephone survey data (Labov, Ash and Boberg fc.) showed this to be the case across WNE with exception of the very northern city of Burlington, Vermont. Words like bad and stack are pronounced with [eə], and words like stand and can are pronounced [εə​].

Labov (1991: 12) suggests that unified raising of TRAP/BATH/DANCE is a pivot condition for the NCCS (Northern Cities Chain Shift). Boberg (2001: 11) further argues that the NCCS may thus have had its beginnings in northwestern NE. The existence of this raising pattern is surprising if one accepts the reported lack of BATH-raising in the LANE data (Kurath 1939-43), especially given that Labov, Ash and Boberg (fc.) does not show this to be an incipient vigorous change: older speakers show more raising than younger speakers in Hartford, CT, Springfield, MA, and Rutland, VT (Boberg 2001: 19).