Table Of ContentProsody:
Theory and Experiment
Speech and Language Technology
Text~
VOLUME 14
Series Editors
Nancy Ide, Vassar College, New York
Jean Veronis, Universite de Provence and CNRS, France
Editorial Board
Harald Baayen, Max Planck Institute for Psycho linguistics, The Netherlands
Kenneth W. Church, AT & T Bell Labs, New Jersey, USA
Judith Klavans, Columbia University, New York, USA
David T. Barnard, University of Regina, Canada
Dan Tufis, Romanian Academy of Sciences, Romania
Joaquim Llisterri, Universitat Autonoma de Barcelona, Spain
Stig Johansson, University of Oslo, Norway
Joseph Mariani, LIMSI-CNRS, France
The titles published in this series are listed at the end of this volume.
Prosody:
Theory and Experiment
Studies Presented to Gosta Bruce
Edited by
Merle Horne
University of Lund, Sweden
,
•
SPRlNGER-SCIENCE+BUSINESS MEDIA, B.Y.
Library ofCongress Cataloging-in-Publication Data
Prosody, theory and experiment: studies presented to Găsta Bruce I edited by Merle Home.
p. cm. -- (Text, speech, and information technology ; v. 14)
Includes index.
ISBN 978-90-481-5562-0 ISBN 978-94-015-9413-4 (eBook)
DOI 10.1007/978-94-015-9413-4
1. Prosodic analysis (Linguistics) 1. Bruce, Găsta, 1947-II. Home, Merle. ID. Series.
P224 .P77 2000
414'.6--dc21
00-060904
Printed on acid-free paper
AII Rights Reserved
© 2000 by Springer Science+Business Media Dordrecht
Originally published by Kluwer Academic Publishers in 2000
Softcover reprint of the hardcover 1s t edition 2000
No part of the material protected by this copyright notice may be reproduced or
utilized in any form Of by any means, electronic or mechanical,
including photocopying, recording or by any information storage and
retrieval system, without written permission from the copyright owner.
CONTENTS
INTRODUCTION
Merle Horne ........................................................................................................ 1
1. TONAL ELEMENTS AND THEIR ALIGNMENT
Janet Pierrehumbert ......................................................................................... 11
2. BRUCE, PIERREHUMBERT, AND THE ELEMENTS OF
INTONATIONAL PHONOLOGY
D. Robert Ladd. ................................................................................................. 37
3. LEVELS OF REPRESENTATION AND LEVELS OF ANALYSIS FOR
THE DESCRIPTION OF INTONATION SYSTEMS
Daniel Hirst, Albert Di Cristo and Robert Espesser ........................................ 51
4. THE PERCEPTION OF PROSODIC PROMINENCE
Jacques Terken and Dik Hermes ...................................................................... 89
5. THE LEXICAL TONE CONTRAST OF ROERMOND DUTCH IN
OPTIMALITY THEORY
Carlos Gussenhoven ....................................................................................... 129
6. MODELING THE ARTICULATORY DYNAMICS OF TWO LEVELS
OF STRESS CONTRAST
Mary E. Beckman and K. Bretonnel Cohen .................................................... 169
7. PHRASE-LEVEL PHONOLOGY IN SPEECH PRODUCTION
PLANNING: EVIDENCE FOR THE ROLE OF PROSODIC STRUCTURE
Stefanie Shattuck-Hufoagel ............................................................................ 201
8. THE INTERACTION OF CONSTRAINTS ON PROSODIC PHRASING
Elisabeth Selkirk ............................................................................................. 231
9. PROSODIC BOUNDARY DETECTION
Mari Ostendorf .................................... , .......................................................... 263
10. TIMING IN SPEECH: A MULTI-LEVEL PROCESS
Nick Campbell ................................................................................................. 281
11. A CORPUS-BASED APPROACH TO THE STUDY OF SPEAKING
STYLE
Julia Hirschberg ............................................................................................. 335
INDEX ............................................................................................................. 351
INTRODUCTION
The study of prosody is perhaps the area of speech research which has
undergone the most noticeable development during the past ten to fifteen
years. As an indication of this, one can note, for example, that at the latest
International Conference on Spoken Language Processing in Philadelphia
(October 1996), there were more sessions devoted to prosody than to any other
area. Not only that, but within other sessions, in particular those dealing with
dialogue, several of the presentations dealt specifically with prosodic aspects
of dialogue research. Even at the latest Eurospeech meeting in Rhodes
(September 1997), prosody, together with speech recognition (where several
contributions dealt with how prosodic cues can be exploited to improve
recognition processes) were the most frequent session topics, despite the fact
that th'ere was a separate ESCA satellite workshop on intonation in conjunction
with the main Eurospeech meeting which included over 80 contributions. This
focus on prosodic research is partly due to the fact that developments in speech
technology have made it possible to examine the acoustic parameters
associated with prosodic phenomena (in particular fundamental frequency and
duration) to an extent which has not been possible in other domains of speech
research. It is also due to the fact that significant theoretical advances in
linguistics and phonetics have been made during this time which have made it
possible to obtain a better understanding of how prosodic parameters function
in expressing different kinds of meaning in the languages of the world.
One of the researchers who has made a significant contribution in shaping
the methodology and goals of prosody research is Gosta Bruce. His studies of
Swedish intonation in sentence perspective have involved both theoretical
modelling and experimental phonetic studies testing the theoretical claims.
Perhaps the most influential of his contributions was the compositional
analysis of Swedish intonational contours into word accents, sentence accent
(associated with focus) and terminal juncture (boundary tones) which realize
different combinations of two phonological level tones Hand L. This insight
into higher-level patterning of prosodic patterns led other researchers to apply
the same methods to other languages. Janet Pierrehumbert shows in her
contribution to this volume "Tonal Elements and their Alignment", how her
model of English intonation was influenced substantially by Bruce's model of
Swedish accent and intonation. In it, English intonation is also modelled using
two underlying tones. The different pitch accents, phrase accents and boundary
tones, defined in terms of Hand L tones, constitute basic elements in a
grammar for generating intonation contours.
Another contribution made by Bruce, as Pierrehumbert shows in her chapter
consisted in showing how different tonal properties can be assigned to
M. Horne (ed.), Prosody: Theory and Experiment, 1-10.
@ 2000 Kluwer Academic Publishers.
2 MERLE HORNE
different levels of prosodic structure, i.e. how the different tonal components
could be assigned to word accents, phrasal (focal) accents and boundary tones.
A further hallmark of Bruce's work, as Pierrehumbert points out, was that he
contributed to our understanding of how tonal representations are associated
with the segmental string, for example, the difference between the two word
accents in Swedish is explained in terms of a timing difference in the
association of the starred tonal-component of the word accent representations
HL * (Accent I) and H*L (Accent II) with the stressed vowel. All these basic
ideas were taken up by Pierrehumbert in her analysis of English, a language
which differs prosodically in many respects from Swedish. For example, unlike
Swedish, English pitch accents are not properties of words but rather post
lexical reflexes of pragmatic aspects of an utterance. English is also
characterized by a larger inventory of pitch accents. In her contribution,
Pierrehumbert discusses the main features of her model as well as
modifications (e.g. reduction in the number of pitch accents, the treatment of
pitch range choice and down step) which it has experienced since its debut in
1980. These have resulted mainly from experimental work in collaboration
with Mark Liberman and Mary Beckman. As Pierrehumbert shows, the
empirical research has also raised questions related to the issues of tonal
alignment as well as locality and lookahead in tonal implementation. A better
understanding of the pragmatic meanings associated with the pitch accents has
also been obtained in recent years due to work with Julia Hirschberg and
practical studies of intonational variation in large data-bases have been made
possible due to the development of the ToBI (Tones and Break Indices)
transcription system based on Pierrehumbert's model.
In his chapter, "Bruce, Pierrehumbert, and the Elements of Intonational
Phonology", D.R. Ladd takes up a number of theoretical problems
surrounding the nature of tones and tonal association that arise from a
comparison of Bruce's ideas and related auto segmental treatments. For
example, whereas Bruce's Hand L tones correspond to concrete "local
maxima and minima in the contour" - turning points - Pierrehumbert's tones
do not necessarily correspond to turning points, nor do turning points always
reflect the phonetic realization of a tone. That is to say, the tones in her
analysis of English are in some cases more abstract than Bruce's and resemble
more the underlying tones in tone languages. Ladd raises the question as to
how abstract should analyses of tone be in languages like English, which is
assumed to have only post-lexical or intonational uses of tones. As opposed to
languages with lexical tone, where one can observe alternations in the shape of
morphemes and words in different contexts, languages with only post-lexical
(intonational) uses of tone often do not allow stringent control over the
identification of tones. Ladd also takes up questions regarding the status of
'starred' tones. These have been used by Pierrehumbert in representing English
bitonal accents and also retrospectively by Bruce in the representation of
INTRODUCTION 3
Swedish word accents. As Ladd shows, it is not clear, however, what the
defining characteristic of the star is. Furthermore, he provides evidence that
shows that it is not always straightforward how the alignment between a
starred tone and the segmental string should take place. Ladd further takes up
the distinction between association and alignment, where association is seen as
an abstract phonological "belonging together" that makes no precise
predictions about temporal coordination; alignment, on the other hand, "is
specified independently of the identity of the tonal string". Association is
"digitial", whereas alignment is "analogue".
In their contribution "Levels of Representation and Levels of Analysis for
the Description of Intonational Systems", Daniel Hirst, Albert Di Cristo and
Robert Espesser discuss a number of issues related to the phonetics/phonology
interface as well as the relationship of the phonological component with the
higher-level syntactic and semantic components. In particular those issues that
are relevant for deciding what kinds of information should be incorporated in
the phonetic ('surface phonological') transcription of prosodic parameters in
cross-linguistic studies are addressed. They distinguish between 'functional
representations' that provide information required for the syntactic and
seman~ic interpretation of an utterance's prosody and 'formal representations'
which provide information related to the pronunciation of an utternace. Since
there is not a one-to-one correspondance between these two types of
information in languages of the world, the possibility of making cross
linguistic studies relies on the ability to separate these two forms of
representation in a universal theory of language structure. Language-specific
parameters then should specify the mapping between form and functional
categories. One specific problem discussed is how to derive an optimal
symbolic phonetic representation for a FO curve on the basis of what we know
about related physiological and perceptual factors. The design and evaluation
of the MOMEL algorithm developed at the University of Aix-en-Provence for
automatic modelling of and synthesis of FO curves in a number of languages is
discussed in detail. The phonetic transcription system (INTSINT) designed to
allow collection and classification of intonational data in languages at
preliminary levels of analyses where pitch accent inventories are not known, is
also taken up and discussed. Also discussed are possible ways in which the
system could be modified to integrate into the transcription discourse
information on variation in overall range and register within intonational units.
Finally, a sketch of the way in which cross-linguistic differences between
intonation systems can be formalized in terms of phonological representations
relating prosodic constituents and tones is presented using data from English
and French.
"Perception of Prosodic Prominence" in particular perceptual judgements
associated with variation in accentual patternings is the topic of Jacques
Terken and Dik Hermes' chapter. They discuss different typologies of
4 MERLE HORNE
prominence that have been proposed since the time of Trager and Smith and
conclude that there is phonetic evidence for at least four types of prominence
categories: reduced, full, stressed and accented. Further they take up the issue
of frequency scales used in the study of speech intonation and address the
question as to which scale best expresses equivalences in the pitch ranges of
men and women and which scale best expresses excursion sizes of pitch
movements related to the perception' of prominence (as opposed to
'liveliness'). They conclude that experimental evidence points to the optimality
of the ERB-rate scale for representing excursion equivalences associated with
accentual prominences and discuss the possible perceptual processes which
may account for this. Variations in the strength of the prominence category
'accent' are known to be related both to the local phonetic characteristics of
the pitch movement (e.g. size, slope, timing) as well as to more global
characteristics such as declination. Terken and Hermes discuss models for
accounting for the variation in accent strength of both single and mUltiple
accents in an utterance. Two models, a High-Level (HL) model and a Pitch
Level Difference (PLD) model are used to explain subjects' judgements of
strength relations between different pitch movements. One observed stable
effect of the perception experiments involving single accents is that falls
induce greater strength than the rise and the rise-fall for the same excursion
sizes. In the modelling of the relative strength relations between two or more
accents within the same utterance, the situation is complicated due to effects
from both declination and speaker-specific pitch range, as welI as the mutual
effect of the prominence of accents on each other's perceived prominence. A
survey is made of experimental results made by a number of researchers on
this intricate problem. The need for a reliable way of transcribing prominence
relations between accents both within and across different pitch registers is
also discussed and the authors conclude by pointing to the need for more work
in the development of theories of prominence and in relating them to issues in
language processing.
Carlos Gussenhoven discusses an interesting case of interaction between
tone and intonation at the ends of phrases in his chapter entitled "The Lexical
Tone Contrast of Roermond Dutch in Optimality Theory". He shoes how
constraint-based Optimality Theory alIows one to better understand a number
of generalizations related to the phonological behaviour of the two tonal word
accents and the intonation (focus and boundary) tones in the Roermond dialect.
These include: the neutralization of the lexical tone contrast in nonfocussed
nonfinal position, the spreading of the final boundary tones into the phrase, the
assimilation ofthe lexical H-tone to L after a focal L-tone in the same sYlIable
and, most interestingly, infixation of the phrasal boundary tones before the
lexical tone. In particular, it is shown that an explanation for the final
generalization concerning the 'tonal reversal' phenomenon in Roermond
cannot be naturally provided by a derivational rule-based description since it
INTRODUCTION 5
leads to "an insoluable ordering paradox". By using the concept of alignment
constraints within Optimality theory, however, the hierarchical ranking of
these constraints can be used to determine which tone will be given preference
at the end of a phrase. Gussenhoven also takes up the distinction between the
concepts 'association' and 'alignment' and uses it to account for the two
different patterns of leftward tone spreading in Roermond: whereas
"alignment locates tones with reference to the edges of (phonological and
morphological) constitutents, association creates a structural connection with a
tone-bearing unit". All tones are aligned according to this view, but only some
are associated. Association does not occur when there is no free tone bearing
unit (TBU) available which is seen to be the case in Roermond when the more
freely-timed case of tone spreading is compared with the more accurately
timed case where a TBU is available.
Timing of tonal events relative to critical points in the segmental
representation of a text is now understood to be an important parameter in
relating meaning contrasts with sound structure. There is, however, another
aspect of timing that is relevant to the issue of tune-text association and that is
the timing of articulatory gestures in the production of the segments to which
intonational events such as pitch accents and boundary tones are anchored.
This is the topic of Mary Beckman and Bretonnel Cohen's chapter "Modelling
the Articulatory Dynamics of Two Levels of Stress Contrast". In this
contribution, differences in segmental timing control associated with "word
stress" and "sentence stress" are studied in an experiment involving
articulatory kinematics and the results are discussed in light of three different
models of articulatory timing: a 'truncation' model, a 'rescaling' model and a
'hybrid' model. Jaw movement data involving durations, amplitudes and peak
velocities for jaw opening and closing movements for accented, unaccented
heavy and reduced CVC ([pap ]/[PdP]) sequences uttered at 3 different speech
tempi are seen to indicate the same relational effects of stress at both levels of
prosodic structure. Movement durations were longest for the vowels in
accented position and shortest for the reduced vowel, with accent producing a
much smaller effect than syllable weight. Movement amplitudes and peak
velocities show the same pattern as duration: accented syllables have the
largest and fastest movements, while the reduced vowel showed the smallest
and slowest movements. Here also, accent had a considerably smaller effect
than syllable weight. However, the relatively more prominent sequences in
each stress contrast pair had smaller velocities than expected for their larger
amplitudes. These observations are explained by a hybrid model which
changes both between- and within-gesture parameters by combining the
between-gesture shortening mechanism of the truncation model as well as the
gestural settling time and displacement changes of the rescaling model. It is
suggested that the lengthening observed in accented sequences as opposed to
unaccented sequences is a considerably more subtle version of the same effect
