Dynamic and perceptual constraints of loud speech

In an investigation of the production of loud speech, it is found that, in comparison with normal speech, these productions are characterized by a substantially lowered jaw position for all vowels. On the basis of these results, we examine whether, for loud speech, speakers maintain tongue constrictions typical for normal vowel production in spite of the lowered jaw position, or if the tongue follows the jaw using constrictions atypical for the particular vowel. Acoustic analyses of the loud tokens show an increase in F1, thus indicating a lowering of the tongue. Tests show, however, that listeners perceive the intended vowel quality, and not that which might be inferred from the loud formant values. The characteristics of the loud speech targets will be discussed in light of the dynamic constraints of the articulatory system and the perceptual constraints set by the listener.