Abstract
Electromyographic techniques were employed to discover which, if any, intrinsic and extrinsic tongue muscles displayed a difference in overall amount of activity corresponding to the traditional tense-lax distinction between members of the English vowel pairs /i - Ị/, /e - ε/, and /u - û/. Although some muscles revealed a consistent difference, most did not. Even for those muscles where a tense-lax difference was found, the data do not support the notion that tension was a necessary or sufficient differentia of production.