American English monophthong tenseness

In General American English, the point vowels of the F2 – F1 verus F1 quadrilateral, [i], [u], and [ɑ] are tense. More generally, Lindau noted the connection between acoustic peripherality and vowel tenseness [Lindau, M. (1975). “Vowel Features.” Working Papers, Phonetics Laboratory, Lund University, 11, p. 1]. In the case of [ae], it is the tensing of this point vowel that initiated the Northern Cities Chain Shift [Labov, W. (1994). Principles of Linguistic Sound Change: Internal Factors. Blackwell Publishers, Malden, MA]. The theses of this talk are firstly that a high degree of acoustic sensitivity to area function change is the reason that peripherality is highly correlated with tenseness. However the reason for the acoustic sensitivity of [ae] is different than it is for the other three point vowels. Second, a more fundamental characterization of tenseness is in its articulatory kinematics during production. The reason for this has to do with the persistence of tenseness with diachronic sound change away from the periphery. Perhaps, though, tense/lax changes appear to be more likely on the periphery than elsewhere.