The Phonetic Patterning of Spontaneous American English Discourse Steven Greenberg, Hannah Carvey,...

The Phonetic Patterningof

Spontaneous American English Discourse

Steven Greenberg, Hannah Carvey, Leah Hitchcock and Shuangyu ChangInternational Computer Science Institute1947 Center Street, Berkeley, CA 94704

{steveng, hmcarvey, leahh, shawnc}@icsi.berkeley.edu

Acknowledgements and Thanks

Research FundingU.S. Department of DefenseU.S. National Science Foundation

For Further Information

Consult the web site:

www.icsi.berkeley.edu/~steveng

OVERTURE

A Central Challenge for Models of Speech Recognition

Pronunciation Variability of Real SpeechPronunciation patterns encountered in everyday life are extremely diverse

Pronunciation Variability of Real SpeechPronunciation patterns encountered in everyday life are extremely diverse There are literally dozens of ways in which common words are pronounced

Pronunciation Variability of Real SpeechPronunciation patterns encountered in everyday life are extremely diverse There are literally dozens of ways in which common words are pronounced

(as the following two slides illustrate for the word “AND” based on manual phonetic annotation of a corpus comprising telephone dialogues)

How Many Pronunciations of “and”?

82 ae n63 eh n45 ix n35 ax n34 en30 n20 ae n dcl d17 ih n17 q ae n11 ae n d

7 q eh n7 ae nx6 ae ae n6 ah n5 eh nx4 uh n4 ix nx4 q ae n dcl d3 eh n d3 q ae nx

3 eh2 ae n dcl2 ae2 ax m2 ax n d2 ae eh n dcl d2 eh n dcl d2 ax nx2 q ae ae n2 q ix n2 ix n dcl d2 ih 2 eh eh n2 q eh nx2 ix d n1 eh m1 ax n dcl d1 aw n1 ae q1 eh dcl

N Pronunciation N Pronunciation

Canonical pronunciation

How Many Pronunciations of “and”?

1 ah nx1 ae n t1 eh d1 ah n dcl d1 ey ih n dcl1 ae ix n1 ae nx ax1 ax ng1 ay n1 ih ah n d1 ae hh1 ih ng1 ix1 ae n d dcl1 ix dcl d1 ae eh n1 hh n1 ix n t1 ae ax n dcl d1 iy eh n

1 m1 ae ae n d1 nx1 q ae ae n1 q ae ae n dcl d1 q ae eh n dcl d1 q ae ih n1 aa n1 q ae n d1 ? nx1 q ae n q1 eh n m1 q eh en dcl1 eh ng1 q eh n q1 em1 q eh ow m1 q ih n1 q ix en1 er

N Pronunciation N Pronunciation

Pronunciation Variability of Real SpeechThe are literally dozens of ways in which common words are pronounced

And as the following slide illustrates for the 20 most frequent words from the same corpus (Switchboard)

Pronunciation Variability of Real SpeechThe are literally dozens of ways in which common words are pronounced

And as the following slide illustrates for the 20 most frequent words from the same corpus (Switchboard)

(which together account for 35% of the word tokens in the corpus)

1 I 6 4 9 5 3 5 3 a y

2 a n d 5 2 1 8 7 1 6 a e n

3 th e 4 7 5 7 6 2 7 d h a x

4 y o u 4 0 6 6 8 2 0 y ix

5 th a t 3 2 8 1 1 7 1 1 d h a e

6 a 3 1 9 2 8 6 4 a x

7 to 2 8 8 6 6 1 4 tc l t u w

8 k n o w 2 4 9 3 4 5 6 n o w

9 o f 2 4 2 4 4 2 1 a x v

1 0 it 2 4 0 4 9 2 2 ih

1 1 y e a h 2 0 3 4 8 4 3 y a e

1 2 in 1 7 8 2 2 4 5 ih n

1 3 th e y 1 5 2 2 8 6 0 d h e y

1 4 d o 1 3 1 3 0 5 4 d c l d u w

1 5 s o 1 3 0 1 4 7 4 s o w

1 6 b u t 1 2 3 4 5 1 2 b c l b a h tc l t

1 7 is 1 2 0 2 4 5 0 ih z

1 8 lik e 1 1 9 1 9 4 6 l a y k c l k

1 9 h a v e 1 1 6 2 2 5 4 h h a e v

2 0 w a s 1 1 1 2 4 2 3 w a h z

2 1 w e 1 0 8 1 3 8 3 w iy

2 2 it's 1 0 1 1 4 2 0 ih tc l s

2 3 ju s t 1 0 1 3 4 1 7 jh ix s

2 4 o n 9 8 1 8 4 9 a a n

2 5 o r 9 4 2 3 3 6 e r

2 6 n o t 9 2 2 4 2 4 m a a q

2 7 th in k 9 2 2 3 3 2 th ih n g k c l k

2 8 fo r 8 7 1 9 4 6 f e r

2 9 w e ll 8 4 4 9 2 3 w e h l

3 0 w h a t 8 2 4 0 1 4 w a h d x

3 1 a b o u t 7 7 4 6 1 2 a x b c l b a w

3 2 a ll 7 4 2 7 2 4 a o l

3 3 th a t's 7 4 1 9 1 6 d h e h s

3 4 o h 7 4 1 7 6 1 o w

3 5 re a lly 7 1 2 5 4 5 r ih l iy

3 6 o n e 6 9 8 7 8 w a h n

3 7 a re 6 8 1 9 4 2 e r

3 8 I'm 6 7 9 2 6 q a a m

3 9 rig h t 6 1 2 1 2 8 r a y

4 0 u h 6 0 1 6 4 1 a h

4 1 th e m 6 0 1 8 2 3 a x m

4 2 a t 5 9 3 6 8 a e d x

4 3 th e re 5 8 2 8 2 2 d h e h r

4 4 my 5 8 9 6 6 m a y

4 5 me a n 5 6 1 0 5 8 m iy n

4 6 d o n 't 5 6 2 1 1 4 d x o w

4 7 n o 5 5 8 7 7 n o w

4 8 w ith 5 5 2 0 3 5 w ih th

4 9 if 5 5 1 8 4 1 ih f

5 0 w h e n 5 4 1 8 3 1 w e h n

5 1 c a n 5 4 2 8 1 5 k c l k a e n

5 2 th e n 5 1 1 9 3 8 d h e h n

5 3 b e 5 0 1 1 7 6 b c l b iy

5 4 a s 4 9 1 6 1 8 a e z

5 5 o u t 4 7 1 9 2 2 a e d x

5 6 k in d 4 7 1 7 2 1 k c l k a x n x

5 7 b e c a u e 4 6 3 1 1 5 k c l k a x z

5 8 p e o p le 4 5 2 1 4 4 p c l p iy p c l l e l

5 9 g o 4 5 5 8 3 g c l g o w

6 0 g o t 4 5 3 2 1 5 g c l g a a

6 1 th is 4 4 1 1 4 7 d h ih s

6 2 s o me 4 3 4 4 8 s a h m

6 3 w o u ld 4 1 1 6 2 9 w ih d c l

6 4 th in g s 4 1 1 5 5 2 th ih n g z

6 5 n o w 3 9 1 1 6 9 n a w

6 6 lo t 3 9 9 4 7 l a a d x

6 7 h a d 3 9 1 9 2 4 h h a e d c l

6 8 h o w 3 9 1 1 5 3 h h a w

6 9 g o o d 3 8 1 3 2 7 g c l g u h d c l

7 0 g e t 3 8 2 0 1 3 g c l g e h d x

7 1 s e e 3 7 6 8 0 s iy

7 2 fro m 3 6 1 0 2 8 f r a h m

7 3 h e 3 6 7 3 9 iy

7 4 me 3 5 5 8 7 m iy

7 5 d o n 't 3 5 2 1 1 4 d x o w

7 6 th e ir 3 3 1 9 2 5 d h e h r

7 7 mo re 3 2 1 1 5 6 m a o r

7 8 it's 3 1 1 4 2 0 ih tc l s

7 9 th a t's 3 1 2 0 1 6 d h e h s

8 0 to o 3 1 6 6 0 tc l t u w

8 1 o k a y 3 1 1 7 4 5 o w k c l k e y

8 2 v e ry 3 0 1 1 3 6 v e h r iy

8 3 u p 3 0 1 1 3 4 a h p c l p

8 4 b e e n 3 0 1 1 5 1 b c l b ih n

8 5 g u e s s 2 9 8 4 2 g c l g e h s

8 6 time 2 9 8 6 2 tc l t a y m

8 7 g o in g 2 9 2 1 1 3 g c l g o w ih n g

8 8 in to 2 8 2 0 1 4 ih n tc l t u w

8 9 th o s e 2 7 1 2 4 2 d h o w z

9 0 h e re 2 7 1 1 2 5 h h iy e r

9 1 d id 2 7 1 3 2 3 d c l d ih d x

9 2 w o rk 2 5 8 6 6 w e r k c l k

9 3 o th e r 2 5 1 4 2 6 a h d h e r

9 4 a n 2 5 1 2 2 8 a x n

9 5 I'v e 2 5 7 4 6 a y v

9 6 th in g 2 4 9 5 2 th ih n g

9 7 e v e n 2 4 7 4 0 iy v ix n

9 8 o u r 2 3 9 3 3 a a r

9 9 a n y 2 3 1 1 2 3 ix n iy

1 0 0 w e 're 2 3 8 2 5 w e y r

How Many Different Pronunciations?

1 I 649 53 53 ay2 and 521 87 16 ae n3 the 475 76 27 dh ax4 you 406 68 20 y ix5 that 328 117 11 dh ae6 a 319 28 64 ax7 to 288 66 14 tcl t uw8 know 249 34 56 n ow9 of 242 44 21 ax v

10 it 240 49 22 ih11 yeah 203 48 43 y ae12 in 178 22 45 ih n13 they 152 28 60 dh ey14 do 131 30 54 dcl d uw15 so 130 14 74 s ow16 but 123 45 12 bcl b ah tcl t17 is 120 24 50 ih z18 like 119 19 46 l ay kcl k19 have 116 22 54 hh ae v20 was 111 24 23 w ah z

Rank Word N #PronMost CommonPronunciation

MCP%Total

The 20 most frequent words account for 35% of the tokens

QUESTION

How DO listeners decode the speech signal given the HUGE variation in

pronunciation?

INTRODUCTION

The Importance of the Syllable

The Importance of the Syllable The analyses to follow are all linked, in some fashion, to the syllable


In order to highlight patterns germane to variation in segmental identity it is necessary to partition the data in terms of ordinal position within the syllable


In order to highlight patterns germane to variation in segmental identity it is necessary to partition the data in terms of ordinal position within the syllable, as well as stress accent (which reflects syllable prominence)



As a consequence, we will examine syllable onsets, nuclei and codas separately in order to gain insight into the underlying patterns



As a consequence, we will examine syllable onsets, nuclei and codas separately in order to gain insight into the underlying patterns

As well as gauge the impact of syllable prominence on phonetic patterning

“J” = JUNCTUREOGI Numbers95 corpus

Syllables and Phonetic Segments Illustrated Syllables generally consist of three constituents - ONSET, NUCLEUS, CODA


Syllables generally consist of three constituents - ONSET, NUCLEUS, CODA

Virtually all syllables contain a NUCLEUS, which is VOCALIC (by definition)

Syllables and Phonetic Segments Illustrated




Most (but not all) syllables also contain an ONSET (usually a CONSONANT)






Many syllables contain a CODA (also typically a CONSONANT)







The most common syllable form in English is Onset + Nucleus + Coda (“Nine”)








Followed in popularity by Onset + Nucleus (“Two”)









Note that onset segments often differ in significant ways from coda segments









Note that onset segments often differ in significant ways from coda segments

And that certain phones are actually “pure junctures” not segments


Syllable Prominence (Stress Accent)Syllables vary with respect to their perceptual (and linguistic) prominence


Some syllables are heavily accented, while others are completely unaccented



A certain proportion of syllables are accented, but not heavily (i.e., intermediate)




In English, the accent system is associated with syllabic stress, which is based on a broad constellation of acoustic parameters that includes:





Duration





Duration, Amplitude





Duration, Amplitude, Vocalic Spectrum





Duration, Amplitude, Vocalic Spectrum, Fundamental Frequency





Duration, Amplitude, Vocalic Spectrum, Fundamental Frequency (among others)






Accent magnitude is an important parameter for understanding pronunciation variation (at least in American English)







A straightforward means of illustrating the difference between accented and unaccented syllables is shown on the following slide







A straightforward means of illustrating the difference between accented and unaccented syllables is shown on the following slide

Which shows hundreds of instances of the word “seven” in a 3-D profile called a STeP (Spectro-Temporal Profile)

Syllable Prominence (Accent) Illustrated

[s]

[eh]

[vx]

[en]

juncture accented syllable

unaccented syllable

“Seven”

mean duration

Full-spectrumperspective

OGI Numbers95

[s] [eh] [vx] [en]

Nucleus

Onset

Ambi-syllabic

Nucleus

Juncture

PART ONE

Phonetic and Prosodic Annotatation

Phonetic Transcription of Spontaneous EnglishTelephone dialogues of 5-10 minutes duration, from the SWITCHBOARD

corpus, have been phonetically transcribed (labeled and segmented)



There is a Lot of Diversity in the Material Transcribed



There is a Lot of Diversity in the Material TranscribedSpans speech of both genders (ca. 50/50%), reflecting a wide range of American

dialectal variation, speaking rate and voice quality





This material has been MANUALLY annotated





This material has been MANUALLY annotated 1 hour LABELED and SEGMENTED at the phonetic-segment level





This material has been MANUALLY annotated 1 hour LABELED and SEGMENTED at the phonetic-segment level 4 hours LABELED at the phone level and SEGMENTED wrt syllable boundaries






The latter material SEGMENTED into PHONES using AUTOMATIC methods







45 minutes of HAND-LABELED, STRESS-ACCENT material







45 minutes of HAND-LABELED, STRESS-ACCENT materialAn additional four hours of stress-accent material automatically labeled







45 minutes of HAND-LABELED, STRESS-ACCENT materialAn additional four hours of stress-accent material automatically labeled (though

NOT used in the current analysis)







45 minutes of HAND-LABELED, STRESS-ACCENT materialAn additional four hours of stress-accent material automatically labeled (though

NOT used in the current analysis)

Transcription SystemA variant of Arpabet, a fairly broad phonetic transcription orthography

Phonetic Transcription of Spontaneous EnglishThe Data are Available at ….

Phonetic Transcription of Spontaneous EnglishThe Data are Available at ….

http://www.icsi.berkeley.edu/real/stp

Annotation of Stress AccentForty-five minutes of the phonetically annotated portion of the Switchboard

corpus was manually labeled with respect to stress accent (prominence)



Three levels of accent were distinguished:




Heavy




Heavy Light




Heavy Light None




Heavy (1) Light (0.5) None (0)





(In actuality, labelers assigned a “1” to fully accented syllables, a “null” to completely unaccented syllables, and a “0.5” to all others)






An example of the annotation (attached to the vocalic nucleus) is shown below (where the accent levels could not be derived from a dictionary)







In this example most of the syllables are unaccented, with two labeled as lightly accented (0.5)







In this example most of the syllables are unaccented, with two labeled as lightly accented (0.5) (and one other labeled as very lightly accented (0.25))

The data are available at ….

Annotation of Stress Accent

The data are available at ….

http://www.icsi.berkeley.edu/~steveng/prosody

Annotation of Stress Accent

PART TWO

Stress Accent and Syllable Position

The Importance of Syllable StructureBefore going into the details of phonetic variation at the segmental level

we briefly examine some GENERAL patterns of pronunciation variation that are conditioned by syllable position and stress accent



In the analyses to follow, the phonetically realized data (from the phonetic transcripts) are directly compared to the “canonical” pronunciations (from a dictionary)




The analyses are therefore in terms of “deviation from canonical” pronunciation




The analyses are therefore in terms of “deviation from canonical” pronunciation

Such data serve to illustrate the sort of variation observed that is conditioned by position within the syllable

(i.e., “ONSET” - “NUCLEUS” - “CODA”)

Pronunciation Variation – Syllable and Accent Pronunciation variation is systematic at the level of the syllable


Particularly when stress accent is also taken into account



Both SYLLABLE STRUCTURE and STRESS-ACCENT LEVEL are required for a full account

Pronunciation Variation – Syllable and Accent

All Segments

Pronunciation variation is systematic at the level of the syllable


Both SYLLABLE STRUCTURE and STRESS-ACCENT LEVEL are required for a full account

Pronunciation Variation – Substitutions

NUCLEUSTerritory

Most of the SUBSTITUTION deviations occur in the NUCLEUS


NUCLEUSTerritory


Stress accent level has a profound impact on the probability of substitutions


NUCLEUSTerritory



Particularly in the nucleus


NUCLEUSTerritory



Particularly in the nucleus, but also in the onset


NUCLEUSTerritory



Particularly in the nucleus, but also in the onset (but not in the coda)

Pronunciation Variation – Deletions Most of the DELETION deviations occur in the CODA

CODATerritory


Stress accent has a significant impact on the probability of deletions

CODATerritory



Particularly in the coda

CODATerritory



Particularly in the coda, but also in the onset as well

CODATerritory

Pronunciation Variation – Insertions

ONSETTerritory

Most of the INSERTION deviations occur in the ONSET

Pronunciation Variation – Summary

All Segments Deletions

InsertionsSubstitutions

CODATerritory

ONSETTerritory

NUCLEUSTerritory

Different components of the syllable are “specialized” wrt to pronunciation patterns




CODATerritory

ONSETTerritory

NUCLEUSTerritory

Different components of the syllable are “specialized” wrt to pronunciation patterns (at least with respect to deviation from the canonical form)




CODATerritory

ONSETTerritory

NUCLEUSTerritory


The NUCLEUS is associated with SUBSTITUTIONS




CODATerritory

ONSETTerritory

NUCLEUSTerritory



The CODA is associated with DELETIONS




CODATerritory

ONSETTerritory

NUCLEUSTerritory



The CODA is associated with DELETIONS, and the ONSET with INSERTIONS

PART THREE

Stress Accent and the Vocalic Nucleus

Vowel quality is generally thought to be a function primarily of two articulatory properties – both related to the motion of the tongue

A Brief Primer on Vocalic Acoustics


• The front-back plane is most closely associated with the second formant frequency (or more precisely F2 - F1) and the volume of the front-cavity resonance




• The height parameter is closely linked to the frequency of F1




• The height parameter is closely linked to the frequency of F1

In the classic vowel “triangle,” segments are positioned in terms of the tongue positions associated with their production, as follows:


In the following slides duration is plotted on a 2-D grid, where the x-axis represents the (hypothetical) front-back tongue position

Spatial Patterning of Duration et al.

In the following slides duration is plotted on a 2-D grid, where the x-axis represents the (hypothetical) front-back tongue position (and hence remains a constant throughout the plots to follow)


In the following slides duration is plotted on a 2-D grid, where the x-axis represents the (hypothetical) front-back tongue position (and hence remains a constant throughout the plots to follow)

The y-axis serves as the dependent measure, expressed in terms of either duration or the proportion of fully stressed (or unstressed) nuclei


Vocalic Identity Among Unstressed NucleiThe high, lax monophthongs are almost always unstressed

Vocalic Identity Among Unstressed NucleiThe high, lax monophthongs are almost always unstressed

The low vowels, be they monophthongs or diphthongs, are rarely unstressed

The high vowels are rarely fully stressed

Vocalic Identity Among Fully Stressed Nuclei


The low vowels, be they monophthongs or diphthongs, are far more likely to be fully stressed




An intermediate degree of stress accounts for the other vocalic instances




An intermediate degree of stress accounts for the other vocalic instances (but will not be addressed here)


The vowels of heavily accented syllables are (mostly) pronounced canonically

Vocalic Variation – Importance of Stress Accent

Canonical Pronunciations Non-Canonical Pronunciations


Low vowels are largely the province of accented syllables




Low vowels are largely the province of accented syllables, and

High vowels the province of unaccented syllables






Moreover, there’s a lexical bias towards high vowels for unaccented forms








Moreover, there’s a lexical bias towards high vowels for unaccented forms

That’s reinforced in patterns of deviation from canonical pronunciation

Vocalic Height Deviation from CanonicalVowels are more likely to RISE in height than to descend when unaccented

Amount of Change Direction of Change


Vocalic lowering of height is rare




Most deviations from the canonical maintain vowel height





More than a single height step deviation is uncommon


Vowels are more likely to RISE in height than to descend when unaccented



More than a single height step deviation is uncommon

Virtually all 2-step height deviations occur in unaccented syllables

Vocalic Height Deviation from Canonical


The Vowel Space Under (Full) Stress (Accent) In HEAVILY ACCENTED nuclei there is a relatively even distribution of

segments across the vowel space, with a slight bias towards the front and central vowels

Canonical Vowels Only

In UNACCENTED syllables vowels are confined largely to the high-front and high-central sectors of the articulatory space

The Vowel Space Without (Stress) Accent


In unaccented syllables vowels are confined largely to the high-front and high-central sectors of the articulatory space

The low and mid vowels “get creamed”

The Vowel Space Without (Stress) Accent


Stress accent exerts a profound effect on the character of the vowel space

The Vowel Spaces Compared


Heavily Accented Unaccented


High vowels are largely associated with unaccented syllables






Low vowels are mostly associated with accented forms






Low vowels are mostly associated with accented forms

This distinction between accented and unaccented syllables is of profound importance for understanding (and modeling) pronunciation variation




PART FOUR

Stress Accent’s Impact on Syllable Onsets

Stress Accent and Syllable OnsetsThe onset is often cited as the key syllabic constituent with respect to

“lexical access”



It is therefore of interest to ascertain how the onset’s phonetic realization behaves as a function of accent level




Because of the onset’s key role in lexical access one might assume that its realization would be relatively stable across accent level





Let’s find out!





Let’s find out!

But first ….





Let’s find out!

But first …. A brief primer on place of articulation features





Let’s find out!

But first …. A brief primer on place of articulation features (which is necessary to understand the pronunciation patterns described)

Place of Articulation – A Brief PrimerThe tongue contacts (or nearly so) the roof of the mouth in producing many of the consonantal sounds in English. Place of articulation can also be associated with the lips

From Daniloff (1973)

AnteriorLabial [p] [b] [m]Labio-dental [f] [v] Inter-dental [th] [dh]

CentralAlveolar [t] [d] [n] [s] [z]

PosteriorPalatal [sh] [zh]Velar [k] [g] [ng]

ChameleonRhoticized [r]Lateral [l]Approximant [hh]

ANTERIOR

CENTRALPOSTERIOR

Segmental Identity and Stress AccentAnd before we examine the segmental patterns in detail, a brief primer on

the interpretation of these data ….

Road Map - How to Interpret the DataCompare the numbers in the YELLOW and ORANGE columns

Can = Canonical formTrans = Transcribed (i.e., phonetically realized)

Accent

Segment Can Trans Can Trans Can Trans Can Trans

p 203 205 153 153 94 94 450 452

b 126 127 227 225 214 190 567 542

m 137 137 211 211 116 110 464 458

f 136 136 104 104 113 103 353 343

v 35 33 58 58 108 93 201 184

th 62 61 102 100 28 26 192 187

TotalHeavy Light None

Accent


p 203 205 153 153 94 94 450 452

b 126 127 227 225 214 190 567 542

m 137 137 211 211 116 110 464 458

f 136 136 104 104 113 103 353 343

v 35 33 58 58 108 93 201 184

th 62 61 102 100 28 26 192 187



Most numbers in the YELLOW / ORANGE columns will be similar

Numbers refer to instances of CANONICAL and OBSERVED (“transcribed”) segments


Accent


p 203 205 153 153 94 94 450 452

b 126 127 227 225 214 190 567 542

m 137 137 211 211 116 110 464 458

f 136 136 104 104 113 103 353 343

v 35 33 58 58 108 93 201 184

th 62 61 102 100 28 26 192 187




Indicating that the phonetic realization of the segment is canonical (“C”)


Road Map - How to Interpret the Data

Accent


p 203 205 153 153 94 94 450 452

b 126 127 227 225 214 190 567 542

m 137 137 211 211 116 110 464 458

f 136 136 104 104 113 103 353 343

v 35 33 58 58 108 93 201 184

th 62 61 102 100 28 26 192 187


Compare the numbers in the YELLOW and ORANGE columns



A large disparity is marked with a blue box and indicates that there is a significant affect on pronunciation


Road Map - How to Interpret the Data

Accent


p 203 205 153 153 94 94 450 452

b 126 127 227 225 214 190 567 542

m 137 137 211 211 116 110 464 458

f 136 136 104 104 113 103 353 343

v 35 33 58 58 108 93 201 184

th 62 61 102 100 28 26 192 187


Compare the numbers in the YELLOW and ORANGE columns



A large disparity is marked with a blue box and indicates that there is a significant affect on pronunciation

And is labeled on the tables to follow as “N” (non-canonical)


Syllable Onset Statistics – ANTERIOR PlaceStress accent has relatively little impact on anterior onset segments

Place of Articulation Approximants

C = Canonical realization across accent levels

N = Non-canonical realization, No = Non-canonical in unaccented syllables


EXCEPT for [dh] and [y]





EXCEPT for [dh] and [y]

[dh] (as in “the” and “them”) tends to delete in many function words, as does [y] (as in “you”), although to a lesser extent than [dh]




Central segments tend to “disappear” under (absence of) stress (accent), particularly in unaccented syllables (No)

Syllable Onset Statistics – CENTRAL Place




Central segments tend to “disappear” under (absence) of stress (accent), particularly in unaccented syllables (No)

There is also a tendency for flaps ([dx] and [nx]) to insert under similar conditions, indicating that such elements substitute for the full forms

Syllable Onset Statistics – CENTRAL Place




Syllable Onset Statistics – CENTRAL PlaceCentral segments tend to “disappear” under (absence) of stress (accent),

particularly in unaccented syllables (No)

There is also a tendency for flaps ([dx] and [nx]) to insert under similar conditions, indicating that such elements substitute for the full forms

In accented syllables, central (non-flap) segments are canonical in identity




Syllable Onset Statistics – POSTERIOR PlacePosterior segments are remarkably stable in onset position




Posterior segments are remarkably stable in onset position

The only significant “deviation” from canonical realization is the intrusion of the glottal stop [q], which lacks phonemic status in English and functions as a “pure juncture” separating syllables




Syllable Onset Statistics – POSTERIOR Place

Syllable Onset Statistics – Place Chameleons“Chameleons” assimilate their place of articulation to the following vowel




Syllable Onset Statistics – Place Chameleons“Chameleons” assimilate their place of articulation to the following vowel

They are relatively stable at syllable onset, EXCEPT in UNACCENTED forms




Pronunciation Patterns – Syllable OnsetsThe ANTERIOR and POSTERIOR onsets are usually CANONICALLY realized

(the exceptions typically function as “pure junctures,” not segments)




Pronunciation Patterns – Syllable OnsetsThe ANTERIOR and POSTERIOR onsets are usually CANONICALLY realized


The CENTRAL and PLACE CHAMELEON onsets are often non-canonical (the former often function as “pure junctures”), particularly in unaccented forms




PART FIVE

Stress Accent’s Impact on Syllable Codas

Syllable Coda Statistics – ANTERIOR PlaceAnterior coda segments are relatively stable under stress (accent)




Anterior coda segments are relatively stable under stress (accent)

The segments [m] and [v] are exceptions




Syllable Coda Statistics – ANTERIOR Place


The segments [m] and [v] are exceptions – they often function as “flaps” in this context, and






The segments [m] and [v] are exceptions – they often function as “flaps” in this context, and

They tend to delete in unaccented syllables





Syllable Coda Statistics – CENTRAL PlaceCentral coda segments are extremely unstable under stress (accent)





Central coda segments are extremely unstable under stress (accent)(except for the voiceless fricative [s])

Syllable Coda Statistics – CENTRAL Place



Accent


t 322 126 575 191 562 172 1459 489

d 200 119 295 127 370 96 865 342

n 311 237 498 381 773 542 1582 1160

s 142 135 202 214 151 155 495 504

z 179 149 258 208 271 221 708 578


The segments [t], [d] and [n] tend to delete in coda position, even in heavily accented syllables



Accent


t 322 126 575 191 562 172 1459 489

d 200 119 295 127 370 96 865 342

n 311 237 498 381 773 542 1582 1160

s 142 135 202 214 151 155 495 504

z 179 149 258 208 271 221 708 578


The segments [t], [d] and [n] tend to delete in coda position, even in heavily accented syllables

The major effect of stress accent is its impact on the probability of segmental deletion (which is somewhat higher in unaccented forms)



Syllable Coda Statistics – POSTERIOR PlacePosterior coda segments are relatively stable under stress (accent)


C = Canonical realization across accent levelsN = Non-canonical realization, No = Non-canonical in unaccented syllables

Posterior coda segments are relatively stable under stress (accent)

The primary exceptions are [ng], which tends to delete in unaccented syllables, the affricate [jh] and the glottal stop [q]



Syllable Coda Statistics – POSTERIOR Place

Syllable Coda Statistics – Place ChameleonsChameleon segments are unstable under stress (accent)




This is particularly true for [l] (for all levels of accent), where many canonical segments transmute into [lg], particularly in accented forms





The segment [r] tends to delete, particularly in unaccented syllables





The segment [r] tends to delete, particularly in unaccented syllables

In many respects coda chameleons behave like vowelsPlace of Articulation Approximants


Pronunciation Patterns – Syllable CodasThe ANTERIOR and POSTERIOR codas are generally canonically realized


C = Canonical realizationN = Non-canonical realization, N0 = Non-canonical in unaccented syllables


Pronunciation Patterns – Syllable CodasThe ANTERIOR and POSTERIOR codas are generally canonically realized


The CENTRAL and PLACE CHAMELEON segments are often non-canonical (and also often function as “pure junctures” or vocalic modifiers)



PART SIX

Onset and Coda Patterns Compared

Comparison of Syllable Onsets and CodasOnsets tend to be more stable (i.e., more canonical) than codas




The coronal segments are unstable in both contexts, but more so in codas





As are the place chameleons (which tend to behave like vowels)





As are the place chameleons (which tend to behave like vowels)

The unstable anterior and posterior phones are mostly “pure junctures”Place of Articulation Approximants


PART SEVEN

The Special Status of Coronal Consonants

There is something “special” about coronal segments (in coda position)

Why do Coronal Coda Segments “Delete” So Often?


A significant proportion of these segments are phonetically unrealized




One potential “explanation” pertains to the trajectory of the second formant(reflecting the front cavity resonance)





The locus (target) frequency of alveolars is ca. 1500-2500 Hz, similar to the second formant of the front and central vowels






Given the preponderance of non-back vowels in the corpus (particularly in unaccented syllables), the second formant for vocalic segments preceding a coda consonant is likely to be between 1500 and 2500 Hz







Thus, the “absence” of a coda segment points, by implication, to the alveolar place of articulation under many circumstances





The locus (target) frequency of ALVEOLAR is ca. 1500-2500 Hz, similar to the second formant of the front and central vowels


Thus, the “absence” of a coda segment points, by implication, to the alveolar place of articulation under many circumstances

This hypothesis is schematically illustrated on the next two slides


HEAVILY ACCENTED Syllables


UNACCENTED Syllables


There is something ELSE that is “special” about coronal segments in codas


Nearly three-quarters of the CODA consonants are CORONALS

Preponderance of Coda Coronals

All accent levels combined (canonical elements)


In contrast is a far more equitable distribution across place among onsets





The disparity in place distribution in coda position implies that coronals are a “default” category





The disparity in place distribution in coda position implies that coronals are a “default” category, and that codas may contain less information than onsets



Stress accent has relatively little impact on the distribution of place in either onset or coda segments

Accent and Preponderance of Coda Coronals

Unaccented and heavily accented levels combined (canonical elements)


Particularly with respect to the preponderance of coronal segments in codas




Particularly with respect to the preponderance of coronal segments in codas

Suggesting that codas are inherently less informative than onsets regardless of accent level



FINALE

What’s Going on in Pronunciation?

With respect to onset and coda segments, there are two basic forms …

What’s Going On? (in pronunciation)

With respect to onset and coda segments, there are two basic forms …(1) those that are relatively stable across accent level, and


With respect to onset and coda segments, there are two basic forms …(1) those that are relatively stable across accent level, and (2) those that are not


With respect to onset and coda segments, there are two basic forms …(1) those that are relatively stable across accent level, and (2) those that are not

Most of the non-continuants (i.e., stops and nasals) are stable when the locus of articulation constriction is either anterior or posterior


With respect to onset and coda segments, there are two basic forms … (1) those that are relatively stable across accent level, and (2) those that are not


The centrally articulated stops and nasals are highly unstable, particularly in coda position and in unaccented syllables – they tend to delete





The place chameleons (i.e., the approximants) are not very stable in either onset or coda position (and behave in many respects like vowels)






The vowels form two basic groups –






The vowels form two basic groups – (1) accented






The vowels form two basic groups – (1) accented and (2) unaccented







The accented vowels are generally canonically realized and quasi-evenly distributed across the vowel space








The unaccented forms tend to concentrate in the high-front and high-central regions of the vowel space









The prevalence of coronal coda consonants is probably linked to the predominance of front and central vowels









The prevalence of coronal coda consonants is probably linked to the predominance of front and central vowels

Such patterns point to the likely importance of efficient information coding in the specification of the phonetic properties of spoken language


That’s All

Many Thanks for Your Time and Attention

The Phonetic Patterning of Spontaneous American English Discourse Steven Greenberg, Hannah Carvey,...

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