“Effect of Genre, Speaker, and Word Class on the Realization

of Given and New Information”

Agustín Gravano & JuliaJulia Hirschberg{agus, julia}@cs.columbia.edu

Interspeech 2006 - Pittsburgh, PAInterspeech 2006 - Pittsburgh, PA

Spoken Language Processing GroupSpoken Language Processing GroupColumbia UniversityColumbia University

Agustín Gravano Interspeech 2006 2

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)

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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?

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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.

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Overview

Materials and Methods Corpus Information status Word classes Features

Results Nouns Verbs

Discussion Conclusions

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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:1. Spontaneous speech recorded and transcribed.

2. Speakers returned and read.

4 speakers (3 male, 1 female).

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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.

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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.

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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.

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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.

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Results: Nouns READ SPON  S1 S2 S3 S4 S1 S2 S3 S4Max Pitch gMean Pitch n n gMin Pitch n gMax Pitch / Context Mean Pitch n n n nMean Pitch / Context Mean Pitch n n n nMin Pitch / Context Mean Pitch n nMax Intensity n n g gMean Intensity n n g gMin Intensity g g gMax Int / Context Mean Intensity n n n nMean Int / Context Mean Intensity n n n g gMin Int / Context Mean Intensity gPause Before n n n n nPause After g g g

n = mean value for the new words is significantly larger than for the given wordsg = mean value for the given words is significantly larger than for the new words

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Results: Verbs READ SPON  S1 S2 S3 S4 S1 S2 S3 S4Max Pitch nMean Pitch g g nMin Pitch g nMax Pitch / Context Mean Pitch g nMean Pitch / Context Mean Pitch gMin Pitch / Context Mean Pitch g nMax Intensity g g g g g g gMean Intensity g g g g g g gMin Intensity g g gMax Int / Context Mean Intensity g g g g gMean Int / Context Mean Intensity g g g g g g g gMin Int / Context Mean Intensity g gPauseBefore g gPauseAfter g

n = mean value for the new words is significantly larger than for the given wordsg = mean value for the given words is significantly larger than for the new words

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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.

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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.

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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.

“Effect of Genre, Speaker, and Word Class on the Realization

of Given and New Information”

Agustín Gravano & JuliaJulia Hirschberg{agus, julia}@cs.columbia.edu

Interspeech 2006 - Pittsburgh, PAInterspeech 2006 - Pittsburgh, PA

Spoken Language Processing GroupSpoken Language Processing GroupColumbia UniversityColumbia University