Prosody--suprasegmental characteristics of speech such as pitch, rhythm, and loudness--is a rich source of information in spoken language and can tell a listener much about the internal state of a speaker. This thesis explores the role of prosody in conveying three very different types of speaker state: paralinguistic state, in particular emotion; pragmatic state, in particular questioning; and the state of spoken language proficiency of non-native English speakers.
Paralinguistics. Intonational features describing pitch contour shape were found to discriminate emotion in terms of positive and negative affect. A procedure is described for clustering groups of listeners according to perceptual emotion ratings that foster further understanding of the relationship between acoustic-prosodic cues and emotion perception.
Pragmatics. Student questions in a corpus of one-on-one tutorial dialogs were found to be signaled primarily by phrase-final rising intonation, an important cue used in conjunction with lexico-pragmatic cues to differentiate the high rate of observed declarative questions from proper declaratives. The automatic classification of question form and function is explored.
Proficiency. Intonational features including syllable prominence, pitch accent, and boundary tones were found to correlate with language proficiency assessment scores at a strength equal to that of traditional fluency metrics. The combination of all prosodic features further increased correlation strength, indicating that suprasegmental information encodes different aspects of communicative competence.
