Prosodic strengthening in the articulation of English /æ/

Abstract

The current study investigates how prosodic strengthening induced by boundary and accent influences the articulation of English low front vowel /æ/ in add, had, and pad. Using Electromagnetic Articulograph (EMA), lip and jaw opening maxima, and tongue dorsum maxima in the horizontal (x) and vertical (y) dimensions were measured during the vocalic production. Boundary-induced strengthening was found in the tongue height (TD-y) dimension in all three words: /æ/ was lower domain-initially than -medially. In other measures, the boundary effect was conditioned by accent and the location of /æ/ within words. Domain-initial strengthening was found with the jaw opening maxima, with larger opening in a higher prosodic position, but it was only when the target words were unaccented. Also, the vowel in add tended to get fronted in a domain-initial position, but the same tendency was not observed in had and pad, suggesting the possibility that initial strengthening effect is conditioned by ‘phonological’ distance from the boundary edge. (had is phonologically similar to pad in that /h/ and /p/ occupy a phonological onset position.) Accent-induced strengthening was robust in all four articulatory measures. Results show that an accent-independent boundary effect is observed on vowels even in a language with lexical stress, and that the articulatory planning for the boundary-induced strengthening on vowels interacts with accent-induced strengthening.