1. The Hierarchical Structure of English Vowel Systems
William Labov,
University of Pennsylvania
PLM 2010

2. The argument for a hierarchical architecture of subsets of English vowels
The binary notation that defines subsets is consistent with the basic phonotactic condition on all English vowels.
The study of chain shifts in progress shows that the consequences of changes in the inventory of a subset are confined to members of that subset.
The directions of chain shifting are governed by the dialect-specific development of peripherality in a given subset of vowels.

3. The argument for a hierarchical architecture of subsets of English vowels
The binary notation that defines subsets is consistent with the basic phonotactic condition on all English vowels.
The study of chain shifts in progress shows that the consequences of changes in the inventory of a subset are confined to members of that subset.
The directions of chain shifting are governed by the dialect-specific development of peripherality in a given subset of vowels.

4. Representations of English vowels
iɪeɛæɑɔʌoʊu
FLEECE KIT FACE DRESS TRAP LOT THOUGHT STRUT GOAT FOOT GOOSE PRICE MOUTH CHOICE
Long
Short
Long and ingliding
Upgliding
Front upgliding
Back upgliding
i u
e ʌ
æ o iy
ey oy ay
iw uw ow aw
ih uh
eh oh
æh ah oh
æh ah
aiawoy
r-less

5. The basic phonotactic condition (BPC)
English words cannot end with a stressed vowel

6. THE PHONOTACTICS OF ENGLISH VOWELS
LONG VOWELS
heat hate height quote hoot
heed hayed hide hoed who’d
he hay high hoe who
SHORT VOWELS
pit pet pat pot putt put
bid bead bad bod bud hood
*[pɪ] *[pɛ] *[pæ] *[po] *[pʌ] *[pʊ]

7. Hierarchical subsystems of English vowels: length is defined independently of phonetic realization
Short
Long V
Upgliding
Long and ingliding Vh
Front upgliding
Back upgliding
Vy Vw

8. Front Back Front Central Back /ɪ/ /ʊ/ /i/ /u/ /e/ /ʌ/ /e/ /ɜ˞/ /o/
Phonemes of American English in broad IPA notation. (Kurath 1977: 18-19)
Checked Free
Front Back Front Central Back
/ɪ/ /ʊ/ /i/ /u/
/e/ /ʌ/ /e/ /ɜ˞/ /o/
/æ/ /ɑ/ /ɔ/
Diphthongs
/ai/
/au/
/oi/
Subsystems of English vowels. Since so much of the logic of chain shifting involves movements out of and into subsystems, our notation must characterize these subsystems in a coherent and systematic manner. The notation must typically used by dialect geographers for American English is actually a form of broad IPA which has little relationship to the principles needed to account for chain shifting

9. see sue say so saw sigh sow soy
Transcribing American English phonemes in broad IPA notation does not reflect the BPC
Checked Free
Front Back Front Central Back
/ɪ/ /ʊ/ /i/ /u/
/e/ /ʌ/ /e/ /ɜ˞/ /o/
/æ/ /ɑ/ /ɔ/
Diphthongs
/ai/
/au/
/oi/
see sue
say so
saw
sigh
sow
soy
Subsystems of English vowels. Since so much of the logic of chain shifting involves movements out of and into subsystems, our notation must characterize these subsystems in a coherent and systematic manner. The notation must typically used by dialect geographers for American English is actually a form of broad IPA which has little relationship to the principles needed to account for chain shifting
(Kurath 1977: 18-19)

10. Binary notation for the word classes of North American English
These are the subsystems of vowels within which the chain shifts take place The binary notation recognized by most linguists is here developed as four sub-systems: the short vowels, the front upgliding vowels, the back upgliding vowels, and the much smaller set (in r-pronouncing dialects) of long and ingliding vowels. Principles of maximal dispersion, maintenance of margins of security operate only within these subsystems. Studies of misunderstandings in spontaneous speech show that they occur primarily within these sub-systems.
This represents the initial position for the description of sound changes in North American English. The labels in these cells refer to historical word classes.
bit put beat suit boot
bet but bait quoit boat bought
bat pot bite bout halve pa,father
KIT FOOT GOOSE
DRESS STRUT FACE CHOICE GOAT THOUGHT
TRAP LOT PRICE MOUTH PALM

11. The argument for a hierarchical architecture of subsets of English vowels
The binary notation that defines subsets is consistent with the basic phonotactic condition on all English vowels.
The study of chain shifts in progress shows that the consequences of changes in the inventory of a subset are confined to members of that subset.
The directions of chain shifting are governed by the dialect-specific development of peripherality in a given subset of vowels.

12. The triggering of chain shifts in North American English dialects
The merger of /o/ in cot, hock, don
with /oh/ in caught, hawk, dawn

13. Formation of the /oh/ class
O.E. oht
though, daughter, brought
wall, wharf, ward, walrus
Mod. E. wal/r
O.E. aw
thaw,straw, claw
O.E. ag
maw,saw, draw ɔ:
M.E. au
O.E. eah <- ah
fought, taught
O.F. a + u
brawn, pawn
Mod.E. o
M.E. av
hawk, laundry
O.F. au
applaud, fraud, because
off, lost, toss, cloth, on, wrong, song, dog (hog, fog, moral, coral,long, song, wrong, strong
O.F. am, an
lawn, spawn

14. Minimal pairs contrasting /o/ and /oh/
cot caught
rot wrought
hock hawk
cock caulk
cod cawed
odd awed
Don dawn
pond pawned
Sol Saul
collar caller
holler hauler
knotty naughty
odd ability audibility

15. The merger of /o/ and /oh/ in cot and caught, etc. (ANAE Map 9.1)
Canada
E.N.E.
The West
W. Pa.

16. Canadian shift in the vowel system of Marsha M., Montreal

17. The Canadian shift: mean values for ANAE Canadian subjects [N=29] vs
The Canadian shift: mean values for ANAE Canadian subjects [N=29] vs. all others [N=410]

18. The Canadian shift nested in the low back merger (ANAE Map 11.7)
Low back merger isogloss 18

19. The Canadian Shift
Short Long ingliding
i u
e ʌ
æ o oh
æh ah iy
ey oy ay
iw uw ow aw
Front upgliding Back upgliding

20. The Pittsburgh Shift
Short Long ingliding
i u
e ʌ
æ o oh
æh ah iy
ey oy ay
iw uw ow aw
Front upgliding Back upgliding

21. The Pittsburgh Shift in the vowel system of Henry K
The Pittsburgh Shift in the vowel system of Henry K., 64, 61 [1996], TS 544

22. The Pittsburgh Shift: Mean values of low vowels for 20 dialects.
PI = Pittsburgh WPA = Western Pennsylvania CA = Canada PR = Providence;
IS = Inland South M = Midland; N = Inland North.

23. The Canadian Shift across subsystems
Long and ingliding vowels
Short vowels
/oh/
/e/
/o/
/æ/
The logic of the chain shifting is illustrated in this diagram. The merger is a collapse of a short vowel /o/ in COT with the long and ingliding vowel /oh/ in CAUGHT. To which subsystem do we assign the collapsed vowel? The decision is again dictated by the phonological facts. While the original short-o was a checked vowel, which cannot occur in stressed word-final position, the merged vowel occurs in free as well as checked position: that is, the vowel of COT is now an allophone of the vowel of CAW. The short vowels then re-adjust automatically to achieve maximal dispersion.

24. The Pittsburgh Shift across subsystems
Long and ingliding vowels
Short vowels
/oh/
/e/
/o/
/æ/
The logic of the chain shifting is again clear: the merger of /o/ and /oh/ represents a migration of short /o/ into the long and ingliding vowels. The short vowel system reacts to this loss not by a backing of /æ/, as in Canada, but instead it is wedge that moves into the vacant position.

25. Forks in the road after the low back merger
/u/
/e/
/ /
/oh/
/æ/
/o/
The logic of the chain shifting is illustrated in this diagram. The merger is a collapse of a short vowel /o/ in COT with tje long and ingliding vowel /oh/. in CAUGHT. Tp which subsystem do we assign the collapsed vowel? The decision is dictated by the phonological facts. While the original short-o was a checked vowel, which cannot occur in stressed word-final position, the merged vowel occurs in free as well as checked position: that is, the vowel of cot is now an allophone of the vowel of caw.

26. The shift of /o/ to /oh/ has consequences only for other members of the short vowel subsystem

27. Binary notation for the word classes of North American English
These are the subsystems of vowels within which the chain shifts take place The binary notation recognized by most linguists is here developed as four sub-systems: the short vowels, the front upgliding vowels, the back upgliding vowels, and the much smaller set (in r-pronouncing dialects) of long and ingliding vowels. Principles of maximal dispersion, maintenance of margins of security operate only within these subsystems. Studies of misunderstandings in spontaneous speech show that they occur primarily within these sub-systems.
This represents the initial position for the description of sound changes in North American English. The labels in these cells refer to historical word classes.
bit put beat suit boot
bet but bait quoit boat bought
bat pot bite bout halve pa,father
KIT FOOT GOOSE
DRESS STRUT FACE CHOICE GOAT THOUGHT
TRAP LOT PRICE MOUTH PALM

28. Distinctive features of American English vowels
Short = 1 mora
Long = 2 morae

29. The argument for a hierarchical architecture of subsets of English vowels
The binary notation that defines subsets is consistent with the basic phonotactic condition on all English vowels.
The study of chain shifts in progress shows that the consequences of changes in the inventory of a subset are confined to members of that subset.
The directions of chain shifting are governed by the dialect-specific development of peripherality in a given subset of vowels.

30. General principles of chain shifting
In chain shifts,
I. Long vowels rise.
II. Short nuclei fall.
II. Back nuclei shift to the front.
--Labov, Yaeger & Steiner 1972

31. Principle I Principle II Principle III
Attested Instances of the general Principles of Chain Shifting in Completed Changes
Principle I Principle II Principle III
raising of (a) lowering of (b) lowering of fronting of
long vowels short vowels diphthongal nuclei back vowels
English North Frisian English Yiddish
German Vegliote Yiddish [Central] Swedish
Yiddish Yiddish [Western] North Frisian
Swedish Swedish Romansh
Frisian North Frisian French
Portuguese Romansch Lettish
Swiss French Vegliote Greek
Romansh Czech Albanian
Greek Lettish Akha
Lithuanian Korean Celtic
Old Prussian
Albanian
Lappish
Syriac
Akha
Celtic
Aramaic
Red = non-Indo-European

32. Cross-Dialectal Comprehension Gating Experiment: Birmingham
Word Phrase Sentence
1. _________ ________________ ___________________________
2. _________ ________________ ___________________________
3. _________ ________________ ___________________________
4. _________ ________________ ___________________________
5. _________ ________________ ___________________________
6. _________ ________________ ___________________________
7. _________ ________________ ___________________________
8. _________ ________________ ___________________________
9. _________ ________________ ___________________________
10. ________ ________________ ___________________________
Cross-Dialectal Comprehension Gating Experiment: Birmingham

33. The Southern Shift (Southern U. S.)
Short Long ingliding
hit, kids
i u
e ʌ
æ o oh
æh ah
set, bed
Danny iy
ey oy ay
iw uw ow aw
beatin’
grade
Guy
wipin’
Front upgliding Back upgliding

34. Notation for the word classes of North American English without distinctive rounding (PLC 3)
These are the subsystems of vowels within which the chain shifts take place The binary notation recognized by most linguists is here developed as four sub-systems: the short vowels, the front upgliding vowels, the back upgliding vowels, and the much smaller set (in r-pronouncing dialects) of long and ingliding vowels. Principles of maximal dispersion, maintenance of margins of security operate only within these subsystems. Studies of misunderstandings in spontaneous speech show that they occur primarily within these sub-systems.
This represents the initial position for the description of sound changes in North American English. The labels in these cells refer to historical word classes.

35. Development of front inglidimg vowels with the Southern Shift
These are the subsystems of vowels within which the chain shifts take place The binary notation recognized by most linguists is here developed as four sub-systems: the short vowels, the front upgliding vowels, the back upgliding vowels, and the much smaller set (in r-pronouncing dialects) of long and ingliding vowels. Principles of maximal dispersion, maintenance of margins of security operate only within these subsystems. Studies of misunderstandings in spontaneous speech show that they occur primarily within these sub-systems.
This represents the initial position for the description of sound changes in North American English. The labels in these cells refer to historical word classes. ih eh

36. The Southern Shift (So. England, Australia)
Short Long ingliding
i u
e ʌ
æ o oh
æh ah iy
ey oy ay
iw uw ow aw
Front upgliding Back upgliding

37. In the Southern Shift, long vowels fall and short vowels rise
The study of current changes in progress indicate that the dimension determining the direction of chain shifts is not length but distance from the outer envelope of phonological space (peripherality).

38. Phonological space with peripheral and nonperipheral tracks

39. General principles of chain shifting (2)
In chain shifts,
I. Tense nuclei rise along a peripheral track
II. Lax nuclei fall along a non-peripheral track

40. General principles of chain shifting (3)
In chain shifts,
I. Peripheral nuclei rise.
II. Nonperipheral nuclei fall.

41. The Canadian shift
bit

42. Specification of peripherality for Canada
Short = 1 mora
peripheral
Long = 2 morae
peripheral

43. Pattern 1 vowel shifting in West Germanic phonological space (the English Great Vowel shift, Middle High German shift, etc.)

44. The Southern Shift
hit
kids
beatin’
set
bed
Danny
grade
Guy
wipin’

45. The Pittsburgh Shift

46. Mean values of 14 vowels for 21 North American dialects

47. The peripherality frame for the normalized ANAE data

48. Insertion of vowel subsystems into West Germanic phonological space

49. Tuw iy
Kuw ey oy u i æh ow oh e ʌ æ ah o ay

50. Interpretation of peripherality frame in Stampe/Donegan dimensions

51. F2 l F1

52. The Southern Shift in the peripherality framework

53. IS IS PI CA

54. Automatic vowel measurement of 7,101 vowels over 50 msec in 57 minute interview with Jean M., 60, Philadelphia [2006]

55. Mean vowels with primary stress of Jean M.

56. Nonperipheral track defined by mean short vowels and peripheral track defined by Vh long and ingliding vowels

57. Back chain shift before /r/ for Jean M.
four
car

58. /ey/ in checked syllables for Jean M., Philadelphia

59. /ey/ in final position for Jean M., Philadelphia

60. 31 tokens of SAY spoken by Jean M., Philadelphia

61. Three vowels from the Southern Shift of Birmingham

62. Lowering of /ey/ along the nonperipheral track for 137 tokens of /ey/ in the Southern Shift of Wendy P., Birmingham

63. Specification of peripherality for the South
Short = 1 mora
peripheral
Long = 2 morae
peripheral

64. The hierarchical structure of the English vowel system as seen through the study of change in progress
All English vowel systems are governed by the basic phonotactic condition, which distinguishes long vowels from short vowels by the license to occur in final stressed position.
For the majority of English dialects which have developed diphthongization of long mid and high vowels. a binary analysis of long vowels is governed by the generalization that no word ends in a stressed vowel.
The vocalic chain shifts in current North American English have been initiated by the migration of a member of one subset into another, largely into the set of long and ingliding vowels.
The chain shifts that follow show the tendency to maximum dispersion within the subsets defined as short, front upgliding, back upgliding and long or ingliding vowels.
The different directions of unidirectional chain shifting are determined by whether the nuclei of a given subsystem are located on the peripheral or nonperipheral track as defined for high and mid vowels.

65. The hierarchical structure of the English vowel system as seen through the study of change in progress (2)
Peripherality does not appear to be defined for low vowels in current West Germanic vowel space. Some low vowels are differentiated by duration, though it has been found that duration contrasts are less stable than other phonetic dimensions (Chen and Wang 1975, Labov and Baranowski 2006)
In the history of English, low vowels show bidirectional movement with alternate fronting and backing. This may be a precondition for the development of dialect divergence in vowel systems (PLC3 Ch. 8).

66. References
Chen, Matthew and William S.-Y. Wang Sound Change: actuation and implementation. Language 51:
Labov, William, Malcah Yaeger & Richard Steiner A Quantitative Study of Sound Change in Progress. Philadelphia: U. S. Regional Survey.
Labov, William and Maciej Baranowski msec. Language Variation and Change 18:
Labov, William Principles of Linguistic Change, Vol. 3: Cognitive and cultural factors. Oxford: Wiley/Blackwell.