Aucun titre de diapositive

1
Workshop on Features, Segments, Tones Konstanz,
30 October-1 November, 2005
Symposium on Phonological Theory Representations
and Architecture CUNY, February 20-21, 2004
Feature-based Explanation in Phonological
Inventories
Features and Sound Inventories
Nick Clements Laboratoire de Phonétique et
Phonologie, Paris E-mail clements_at_idf.ext.jussieu
.fr
Nick Clements Laboratoire de Phonétique et
Phonologie, Paris clements_at_idf.ext.jussieu.fr
2
Summary
Symposium on Phonological Theory Representations
and Architecture CUNY, February 20-21, 2004
Phonological inventories are structured in terms
of a number of interacting principles which
operate on distinctive features, rather than
segments or phonetic parameters. Five general
principles are discussed and exemplified with
respect to data drawn from a large sample of
segment inventories
Features and Sound Inventories
Nick Clements Laboratoire de Phonétique et
Phonologie, Paris E-mail clements_at_idf.ext.jussieu
.fr

• feature bounding
• feature economy
• marked feature avoidance
• robustness
• phonological enhancement

3
INTRODUCTION
4
WHY DO LANGUAGES TEND TO HAVE CERTAIN SETS OF
SPEECH SOUNDS AND NOT OTHERS?

• A common observation not just any set of
  consonants and vowels can make up a sound system.
  
• A central finding of the earliest work in
  phonology was that sound systems are structured
  in terms of correlations defined in terms of
  recurrent features. (see e.g. Trubetzkoy 1939,
  Martinet 1955, Hockett 1955)

5

• In recent years, however, the question of
  inventory structure has been more vigorously
  debated among phoneticians than among
  phonologists. This work has tended to minimize
  the role of features. Examples

• Adaptive dispersion theory (e.g. Lindblom 1986,
  Lindblom Maddieson 1988)
• maximal (or sufficient) dispersion
• articulatory ease
• Gestural economy (Maddieson 1995)
• economize gestures

6

• Work in mainstream Optimality Theory has tended
  to neglect inventory structure, since constraint
  systems evaluate individual forms rather than
  system-wide generalizations.
• See, however, Boersma (1997), Flemming (2002) for
  proposals to incorporate system-level principles
  such as dispersion, symmetry and articulatory
  effort into OT.

• Paul Boersma, Functional Phonology, 1988
• Edward Flemming, Auditory Representations in
  Phonology, 2002

These approaches, too, have sought explanation in
phonetic, rather than phonological principles.
7
ARE FEATURES NECESSARY AT ALL?

• Some phonologists have concluded that
  phonological theory no longer requires a
  restrictive inventory of distinctive features but
  that "phonological representation can include the
  entire sea of predictable or freely varying
  phonetic detail"

(Kirchner, Robert. 2001. "Phonological contrast
and articulatory effort," In Linda Lombardi,
ed., Segmental Phonology in Optimality Theory, p.
112.)
8
A FEATURE-BASED APPROACH

• This talk reviews a range of evidence showing
  that features play a central role in the
  structuring of sound systems.

• It proposes a number of general principles stated
  in terms of features, and
• shows that these principles make largely accurate
  predictions regarding the structure of speech
  sound inventories.

9
FEATURE FRAMEWORK
1. A fairly conservative set of features will be
sufficient for our purposes (e.g. Halle
Clements 1983, Sagey 1986) 2. For phonetic
feature definitions, we assume the framework of
Quantal-enhancement theory as developed by
Stevens and his collaborators (e.g. Stevens
1972, 1989, 2004, Stevens Keyser 1989, 2001)
10
METHOD
11
DATA BASE

• Evidence is drawn primarily from the expanded
  UPSID data base (Maddieson Precoda 1989).
  Properties

• contains 451 phoneme inventories (representing
  6-7 of the world's languages)
• geographically and genetically balanced
• electronic database facilitates rapid searches
• results can be independently verified by others

12
PROBLEMS WITH THE UPSID DATA BASE

• inevitable genetic skewing (e.g. Niger-Congo 55
  languages, Basque 1 language)
• heterogeneity of sources, disagreements in
  analyses
• inclusion of some allophonic details but not
  others (e.g. dental vs. alveolar stops, but not
  apical vs. laminal stops)
• many coding errors

To a considerable exent, these problems are
alleviated by the sheer size of the sample
however, care must be taken in interpreting
results (see Basbøl 1985, Maddieson 1991, Simpson
1999, Clements 2003)
Statistical testing (chi square) is used here to
evaluate trends.
13
FEATURE BOUNDING
14
FEATURE BOUNDING

• Features set an upper limit on the number of
  sounds and contrasts that a language may employ
  in its lexicon and phonology.

1) Sounds
Given a set of n features, a language may have at
most 2n distinctive sounds. For example,

• a language using 2 features can have up to 4
  sounds (22)
• one using 3 features can have up to 8 sounds
  (23), etc.

15
EXAMPLE MAJOR PLACE CATEGORIES

• The features posterior and distributed
  define four major place categories in coronal
  sounds.

apico-
lamino- retroflex
postalveolar/ anterior
anterior
palatal posterior - - - - distributed -
-
16

• 2) Contrasts
• Features also set limits on the number of
  contrasts a language may have.
• Maximum number of contrasts (S S-1) / 2,
  where S number of sounds.
• Example
• 4 sounds define 6 contrasts (4 3) / 2
  6
• Since the two binary features posterior and
  distributed define up to 4 sounds, they
  predict as many as 6 contrasts, and no more.

17
ALL 6 CONTRASTS PREDICTED BY FEATURE THEORY ARE
ATTESTED

• contrast example found in e.g.
• apical anterior vs. laminal anterior apical t
  vs. laminal t Temne
• apical anterior vs. apical posterior apical t
  vs. retroflex ÿ Yanyuwa
• apical anterior vs. laminal posterior apical
  t vs. palatal c Arrernte
• laminal anterior vs. apical posterior laminal
  t vs. retroflex ÿ Arrernte
• laminal anterior vs. laminal posterior laminal
  t vs. palatal c Hungarian
• apical posterior vs. laminal posterior
  retroflex ÿ vs. palatal c Sindhi
• Moreover, no other primary coronal contrasts were
  discovered in either plosives or affricates in a
  survey of several hundred languages (Clements
  1999).

18
PHONETIC CATEGORIES ARE LESS RESTRICTIVE

• Traditional phonetic theory provides 7 (or more)
  different place distinctions within this region
  ("apico-dental", "apico-alveolar",
  "lamino-dental", "lamino-alveolar",
  "palato-alveolar", "retroflex", and "palatal").
  It projects as many as 21 contrasts.
• Max no. sounds Max no. contrasts
• Feature theory 4
  6
• Traditional phonetic theory 7
  21

19
FEATURE ECONOMY
20

• Feature Economy is the tendency to maximize
  feature combinations in a given system
• - Clements (2003a,b) after sources in de
  Groot (1931), Martinet (1955, 1968)
• This principle can be observed in most speech
  sound inventories, regardless of their size.
• ...

21
A STANDARD VARIETY OF ENGLISH 24 CONSONANTS

• ph th tSh kh
• b d dZ g
• f T s S
• v D z Z
• m n N
• w l r y h

• voiced cross-classifies all obstruents
• continuant doubles the number again
• nasal creates nasal stops at three places of
  articulation

22
THE ECONOMY INDEX

• Feature economy can be quantified in terms of a
  measure called the economy index. Given a system
  using F features to characterize S sounds, we can
  define its economy index E (to a first
  approximation) by the expression
• E S/F

• Example English has 24 consonants and requires a
  minimum of 9 features to distinguish them
• labial, dorsal, continuant, voiced,
  glottal, strident, posterior, nasal,
  lateral
• The economy index of the English consonant system
  is therefore 24/9, or 2.7

23
Examples sounds features E English
24 9 2.7 English 1
sound 25 9 2.8 English - 1
feature 24 8 3.0
Feature Economy can now be more exactly defined
as the tendency to maximize E. This goal can
be accomplished either by - increasing the
number of sounds S, or - decreasing the number
of features F
24
TESTING FEATURE ECONOMY

• A testable prediction of feature economy is
  Mutual Attraction
• "A given speech sound will have a higher than
  expected frequency in inventories in which all
  its features are distinctively present in other
  sounds."
• For instance, a stop with a certain laryngeal
  feature L should occur more frequently in systems
  having other stops with the same feature L.
• Let us look at an example.

25
COMPARISONS OF PAIRS OF STOPS SHARING MANNER
FEATURES, BUT DIFFERING IN PLACE

• All comparisons are positive at a high level of
  significance (plt.0001). That is, languages
  having one member of each pair tend strongly to
  have the other.

26
CROSS-CATEGORY ATTRACTION
Feature economy also applies across manner
categories.

• For example, it predicts that a language having
  the sounds
• P T K, B D G, and F S X
• will tend to also have the sounds V Z Ä, thereby
  maximizing the use of voiced and
  continuant.
• Result (Clements 2003)
• voiced labial fricatives V are much more frequent
  than expected in languages also having P, B, and
  F
• analogous results hold for Z and Ä
• these trends are significant at the .0001 level

27
MARKED FEATURE AVOIDANCE
28

• Markedness is understood here as the systematic
  avoidance of certain widely disfavored feature
  values -- the marked values (Trubetzkoy 1939,
  Jakobson 1941, Greenberg 1968, Chomsky Halle
  1968, Kean 1980, Calabrese 1994, 2005, Rice
  2002).
• Markedness counteracts the free operation of
  Feature Economy

• in the absence of markedness, sound systems
  making use of n features would be expected to
  display the theoretical maximum of 2n sounds
• no languages come close to approaching this
  maximum instead, segments characterized by
  marked feature values tend to be avoided

29
Recall the English consonant system
ph th tSh kh b d dZ g f T s S v
D z Z m n N w l r y h
Absent feature combinations correspond largely to
cross-linguistically disfavored consonant types
30
At the same time, Feature Economy counteracts
Markedness
Example voiced fricatives

• voiced fricatives involve the marked feature
  values voiced and continuant.
• voiced fricatives are absent in roughly half the
  world's languages.
• however, due to the effect of feature economy, if
  a language has one voiced fricative, it is twice
  as likely to have another.
• 
  / . . .

31
VOICED FRICATIVES IN UPSID

• labial V (overall 32.6 )
• in languages having no other voiced fricative
  13.5
• in languages having another voiced fricative
  60.3
• coronal Z (overall 38.6 )
• in languages having no other voiced fricative
  16.3
• in languages having another voiced fricative
  73.7
• dorsal Ä (overall 15.5 )
• in languages having no other voiced fricative
  3.3
• in languages having another voiced fricative
  29.2

32
HOW DO WE KNOW WHICH VALUE OF A FEATURE IS MARKED?

• Phonetic approaches
• Phonetic theory involves an extremely rich
  set of interacting principles that
  frequently lead to conflicting
  expectations.
• example which value of nasal is
  marked?
• Statistical approaches
• The likelier (more frequent, more
  predictable) value of a feature is
  its unmarked specification (Kean 1980, Hume 2004)
• A statistical approach has the advantage of
  relating markedness to observable frequency
  distributions that can be readily extracted by
  language learners (Pierrehumbert 2003)

33

• As pointed out by Greenberg (1966) and others,
  markedness is reflected in frequency differences
  at many levels. For example, sounds bearing
  marked feature values tend to be less frequent
• in the lexicon
• in running texts
• in early stages of language acquisition
• in adult sound inventories

34
A PROPOSED CRITERION MARKEDNESS AS NONUBIQUITY

• A feature value is marked if it is absent in some
  language in classes of sounds it which it is
  potentially distinctive otherwise it is
  unmarked. Examples

35
THE MARKED SUBSET PRINCIPLE (MSP)
"Within any class of sounds in which a given
feature F is potentially distinctive, sounds
bearing marked values of F are less frequent
than sounds bearing unmarked values of F" In
other words, languages tend to avoid marked
feature values, regardless of the class of sounds
they occur in. The prediction is that this
principle will hold except where overridden by a
competing principle.
36
SOME PREDICTIONS OF THE MARKED SUBSET PRINCIPLE
( lt is to be read are less frequent than)
a. in the class of vowels, nasal vowels lt oral
vowels (marked feature
nasal) b. in the class of consonants,
sonorants lt obstruents (marked
feature sonorant) c. in the class of
obstruents, fricatives lt stops
(marked feature continuant) Do these
predictions hold? Consider again English. s
37
Prediction (a) nasal vowels lt oral vowels
true (English has no nasal vowels)
Prediction (b) sonorants lt obstruents
true (see below)
ph th tSh kh b d dZ g f T s S v
D z Z m n N w l r y h
Prediction (c) fricatives lt stops
false ! why ?
38
A COMMON TYPE OF EXCEPTION TO THE MARKED SUBSET
PRINCIPLE
The number of marked sounds is often equal to the
number of unmarked sounds. Examples
English fricatives stops Ikwere nasal
vowels oral vowels i iâ u u) I Iâ U U) e
e) o o) E E)