Parenthetical - A Special Type of Prosodic Reduction in Continuous Speech

The current study investigates parenthetical, a type of prosodic reduction in multi-phrase speech paragraphs. Structurally a modifier of its antecedent to provide supplementary information, such reduction creates a lower level in the prosodic hierarchy nested within a discourse-prosodic unit. Perceptual annotation of parenthetical turned out to be consistent across listeners; their acoustic profiles distinctive. Further calculation of information density in relation to allocation of perceived emphasis also demonstrates that parenthetical triggered prosodic reductions are patterned and accountable. Therefore, in spite of low information standing, their existence in the prosodic hierarchy helps facilitate more precise information expression. In sum, current evidence illustrates how information planning is manifested via both emphases and reductions in global context prosody, why parenthetical caused reductions should be understood from a hierarchical perspective within speech context, and how prosodic reduction also plays a crucial role in contributing to comprehensive understanding toward context prosody.