Eyebrow movement as a cue to prominence

INTRODUCTION Speech communication is inherently multimodal in nature. While the auditory modality often provides the phonetic information necessary to convey a linguistic message, the visual modality can qualify the auditory information providing segmental cues on place of articulation, prosodic information concerning prominence and phrasing and extralinguistic information such as signals for turn-taking, emotions and attitudes. Although these observations are not novel, prosody research has largely ignored the visual modality. One reason is the primary status of auditory speech, another is the relatively more complicated generation of visual speech. Most of the work that has been done in multimodal speech perception has concentrated on segmental cues in the visual modality.