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Studying Intonation. Julia Hirschberg CS 4706. Today. Approaches to studying contour meaning Questions people ask Does contour X convey a different meaning from contour Y? Is contour X used more often in context Z than contour Y
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Studying Intonation Julia Hirschberg CS 4706
Today • Approaches to studying contour meaning • Questions people ask • Does contour X convey a different meaning from contour Y? • Is contour X used more often in context Z than contour Y • Despite what people say/think, not all phenomena X are uttered with contour Y • What kind of evidence could we get? • Found data • Laboratory experiments: production, perception • Corpus collection
What features can we look at and how do we obtain them? • Intonation labeling by hand • Acoustic/prosodic analysis by automatic methods • Pitch tracking, pause detection, intensity, duration, speaking rate extraction • Computational linguistic techniques to extract transcript-based (text) features • Part-of-speech • Sentence length, … • What techniques do we use for analysis? • Statistical methods (Splus, Matlab) • Machine learning techniques
Some Sample Approaches • Natural Corpus: Hedberg & Sosa 2002 • Introspective, observational: Wilson 1993, Pierrehumbert & Hirschberg 1990/2 • Laboratory -- Production/Perception: Syrdal & Jilka 2004 • Laboratory – Brain Imaging (e.g. fMRI): Doherty et al
A Prescriptive Approach: Wilson 1993 • Declarative statements fall and yes-no-questions rise? • Wh-questions fall? • Small final rise signals ‘more to come’?
Corpus Studies of Questions: Hedberg & Sosa 2002 • How are yes-no and wh-questions uttered and how might we explain differences? • Where is the nuclear stress? • Where is the semantic ‘focus’? What is the ‘topic’? • Are the ‘wh words’ accented or not? • Corpus: 73 questions Who saw John?/Who didn’t see John? Did John leave?/Didn’t John leave? • 35 whq’s and 38 ynq’s from the McLaughlin Group and Washington Week
Analysis • Intonational labeling (ToBI) from pitch tracks • Topic/focus coding • Frequency distributions of features with question categories • Prosody of ‘locus of interrogation’ • Wh word in wh-questions • Fronted auxiliary in yes-no questions • Results • Ynq’s generally uttered w/ falling or level intonation, not rising (69%) • Wh-q’s most often uttered with falling (80%)
Wh-words (60%) in all wh-questions and neg aux in negative ynq’s (89%) most often uttered with L+H* accent (‘contrastive’ accent) -- why? • Aux in positive ynq’s often deaccented (41%) or realized with L* (17%) accent – why? • Conclusions/open questions: • Why do ynq’s and wh-q’s sometimes rise and sometimes fall? • Locus of interrogation is accented in wh-q’s and in negative ynq’s to “signal interrogative status of sentence” – but not in positive ynq’s “due to need to highlight a following element”
Critique • Is this a good corpus for this investigation? • Size • Genre • What about the speakers?
Syrdal & Jilka 2004 • How are whq’s and ynq’s produced most naturally (for TTS)? • Same initial hypothesis: whq’s fall and ynq’s rise in American English • Different approach: production and perception studies • Production: • 8 (professional) speakers (5F, 3M) • Read transcripts of actual dialogues
Analysis: • Intonational (ToBI) labeling from pitch tracks of extracted questions • Results: • Ynq’s rose in 83% of cases for females and 53% for males • Wh-q’s always fell for females and fell 79% of time for male speakers; wh-q’s and statements generally fell • Nuclear accents in ynq’s: majority L*
Perception studies: acceptability judgments • Forced choice, 12 listeners • Stimuli: Pairs of ynq and whq’s with same voice/different intonation • 17 natural (9 ynq’s, 8 whq’s) • 12 synthesized • 12 subjects (6 and 6) • Judgments: • Ynq: • Natural speech: people preferred standard rise (L* H- H%) • Synthetic speech: no results • Whq: • Natural speech: people preferred falling contours (L- L%) to rising (H-H%) and slightly to ‘continuation rise’ (L- H%) • Synthetic: no preference
Critique • How many questions were produced? • Are professional speakers a good choice? • Read vs. spontaneous speech? For TTS? • Why no results for synthetic speech? • Comparison to Hedberg and Sosa
Doherty et al 2004 • How do people process intonation, e.g., in rising questions vs. falling statements vs. falling questions? She was talking to her father? She was talking to her father. Was she talking to her father. • Research questions: • Where is the ‘prosody’ portion of the brain? • What other sectors is it ‘close’ to and what is their function? • Do particular contours have particular locations?
Method: functional Magnetic Resonance Imaging (fMRI) of subjects presented with digitized recordings • 11 subjects (4M, 7F) • Note experimental condition! • 150 triples, of which each subjects heard only 1 version • She was talking to her father? • Was she talking to her father. • She was talking to her father. • Monitoring task: Is this a question or a statement? • Press one key for question, another for statement
Results: Increase in activation when subjects made judgments about tokens w/ rising intonation -- but not falling, whether syntactic question or syntactic statement • Why? • Semantic processing? No – illocutionary force is same in rising and falling questions • Acoustic processing? Maybe… • Interpreting the rising contour as a question? • Check lesion studies to see if people with damage in these areas can interpret rising contours…
Critique • No rising inverted questions? “Was she talking to her father?”
Next Class • How do we represent intonational variation?