Agustín Gravano & Julia Hirschberg {agus, julia}@cs.columbia.edu Interspeech 2006 - Pittsburgh, PA “Effect of Genre, Speaker, and Word Class on the Realization of Given and New Information” Agustín Gravano & Julia Hirschberg {agus, julia}@cs.columbia.edu Spoken Language Processing Group Columbia University

Agustín Gravano Interspeech 2006 Motivation Speakers of American English tend to: accent references to “new” information, and deaccent references to “old” (or “given”) information. (Chafe 1974, Prince 1981 & 1992, inter alia) Variation of prominence in “given” entities is strongly affected by the persistence of: grammatical function (subject, object, etc.) and position in the sentence. (Terken & Hirschberg, 1994) Agustín Gravano Interspeech 2006

Agustín Gravano Interspeech 2006 Motivation Possible applications: Improve naturalness of TTS systems. Aid ASR. Questions: What are other sources of variation? What is the effect of: speaker? genre? word class? Agustín Gravano Interspeech 2006

Agustín Gravano Interspeech 2006 Main Results Speakers vary the manner in which they realize differences in information status. Speakers tend to produce “given” verbs with higher intensity than “new” verbs, both in read and spontaneous speech. Agustín Gravano Interspeech 2006

Agustín Gravano Interspeech 2006 Overview Materials and Methods Corpus Information status Word classes Features Results Nouns Verbs Discussion Conclusions Agustín Gravano Interspeech 2006

Boston Directions Corpus Hirschberg & Nakatani 1996 Spontaneous and read monologues. 9 increasingly complex direction-giving tasks: Describe how to get to MIT from Harvard. Method: Spontaneous speech recorded and transcribed. Speakers returned and read. 4 speakers (3 male, 1 female). Agustín Gravano Interspeech 2006

Boston Directions Corpus Mean length of tasks: Spontaneous: 111s Read: 84s Excerpt from the spontaneous part of the corpus: first # enter the Harvard Square T stop # and buy a token # then proceed to get on the # Inbound um Red Line # uh subway [...] Corpus size: Spontaneous: ~66m Read: ~50m Prosody labeled using the ToBI convention. Agustín Gravano Interspeech 2006

Agustín Gravano Interspeech 2006 Information Status Prince 1981: Entities are new when first introduced in the discourse. Evoked entities are given. They are already in the discourse. Simple definition: A word w is given if in the current task there is at least one previous occurrence of a word with the same stem. Otherwise, we say that w is new. Agustín Gravano Interspeech 2006

Agustín Gravano Interspeech 2006 Word Classes Automatically labeled the part-of-speech of all the words in the corpus using the Brill Tagger. Categorized words into: Nouns Verbs Adjectives Adverbs Others Significant results only for Nouns and Verbs. Agustín Gravano Interspeech 2006

Agustín Gravano Interspeech 2006 Features Word acoustic features, extracted using Praat: Max, mean, min pitch Max, mean, min intensity Pitch and intensity features were also normalized with respect to the mean value of: ± 1 second around the target word, ± 5 words around the target word, the target word’s Intermediate Phrase. Pause before and after the word. Agustín Gravano Interspeech 2006

Agustín Gravano Interspeech 2006 Results: Nouns READ SPON   S1 S2 S3 S4 Max Pitch g Mean Pitch n Min Pitch Max Pitch / Context Mean Pitch Mean Pitch / Context Mean Pitch Min Pitch / Context Mean Pitch Max Intensity Mean Intensity Min Intensity Max Int / Context Mean Intensity Mean Int / Context Mean Intensity Min Int / Context Mean Intensity Pause Before Pause After n = mean value for the new words is significantly larger than for the given words g = mean value for the given words is significantly larger than for the new words Agustín Gravano Interspeech 2006

Agustín Gravano Interspeech 2006 Results: Verbs READ SPON   S1 S2 S3 S4 Max Pitch n Mean Pitch g Min Pitch Max Pitch / Context Mean Pitch Mean Pitch / Context Mean Pitch Min Pitch / Context Mean Pitch Max Intensity Mean Intensity Min Intensity Max Int / Context Mean Intensity Mean Int / Context Mean Intensity Min Int / Context Mean Intensity PauseBefore PauseAfter n = mean value for the new words is significantly larger than for the given words g = mean value for the given words is significantly larger than for the new words Agustín Gravano Interspeech 2006

Discussion: Variation of intensity in verbs Examples: you get out of the T stop # you cross Massachusetts Avenue [...] you wanna cross Mass Ave opposite that # there's usually a bunch of cabs and and people standing around there # so # then once you've crossed it you're you're in Harvard Yard proper then you're right at the entrance to what is called the Infinite Corridor # and it's called the Infinite Corridor because it's this really long # place you can walk entirely indoors Direct objects of ‘cross’ and ‘call’ are either deaccented or pronominalized in the second and third mentions. With no other salient accented items in their phrases, the given mentions of these verbs are more prominent. Agustín Gravano Interspeech 2006

Discussion: Variation of intensity in verbs Example: so you're going to have to transfer # you transfer by going to Government Center which is inbound The increased intensity of the second mention of ‘transfer’ might be due to the change in its verb form. Similar to Terken & Hirschberg, 1994: Given nouns tend to be accented if they represent a different grammatical function from the first mention. Agustín Gravano Interspeech 2006

Conclusions and Future Work Evidence of: Speaker variation in the way they realize differences in information status. Given verbs tend to be produced with a greater intensity than new verbs. Nouns and verbs behave very differently. Only preliminary results: more work needed. Future Work: Repeat and deepen these analyses on larger corpora of read and spontaneous speech, and in conversation. Agustín Gravano Interspeech 2006

Agustín Gravano & Julia Hirschberg {agus, julia}@cs.columbia.edu Interspeech 2006 - Pittsburgh, PA “Effect of Genre, Speaker, and Word Class on the Realization of Given and New Information” Agustín Gravano & Julia Hirschberg {agus, julia}@cs.columbia.edu Spoken Language Processing Group Columbia University