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

2. 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

3. 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

4. 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

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

6. 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

7. 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

8. 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

9. 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

10. 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

11. 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

12. 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

13. 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

14. 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

15. 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

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