OCP-Driven variation in American English schwa production

Mary Ann Walter

MIT

Introduction

• Languages often avoid sequences with identical elements in close proximity.

• This generalization has been expressed in the linguistics literature as the Obligatory Contour Principle, or OCP.

• Its effects may be seen through constraints on underlying representations, triggering alternations, and blocking alternations.

Introduction• Two OCP effects:

Epenthesis (English inflectional schwa):

pat ~ pats pass ~ passes

[pæt] [pæts], *[pætəs] [pæs] [pæsəz], *[pæs:]

Antigemination:

digibté digbé ‘she/I married’

xararté xararé ‘s/he burned’V-deletion except between 2 identical consonantsClaimed not to have a phonetic counterpart

(McCarthy 1986, Blevins 2005)

Introduction• Recent work has shown OCP effects that are

gradient as well as categorical:– Properties of the lexicon (Frisch 2004; Frisch, Pierrehumbert and

Broe 2004; Berkley 2000)

– Perception of consonantal place (Coetzee 2005)

– Goodness ratings (Berent and Shimron 1997; Berent, Everett and Shimron 2001; Coetzee 2005)

Even phonotactically licit OCP violations have processing effects.

Goal• Determine extent to which phonetic

productions in OCP-violating contexts differ from what is otherwise expected.

Prediction• Vowels will have longer durations when

between identical consonants than non-identical ones.

Exp 1: Method• Subjects (n=9) read aloud the following stimuli from

visual presentation in random order in a soundproof booth, in isolation and in a frame sentence.

b a b a b o t

ee d d ee

oo g g oo

“Bababot. Do you know what a bababot is?”

Exp 1: Results• Schwa duration is significantly longer when

produced between two identical consonants than non-identical ones (RM ANOVA, p<.001).

• This asymmetry holds for each individual subject.

0

10

20

30

40

50

60

70

80

90

100

Subject

Sc

hw

a d

ura

tio

n, m

s

OCP

non-OCP

Exp 2: Method• Subjects (n=8) read aloud the following stimuli from

visual presentation in random order in a soundproof booth, in isolation and in a frame sentence.

p a p ee n

k k oo l

t t

“She papeens a lot. She’s a papeener now.”

Exp 2: Results• Again, schwa duration is significantly longer when

produced between two identical consonants than non-identical ones (RM ANOVA, p<.001).

• Again, the asymmetry is consistent across subjects.

0

10

20

30

40

50

60

70

80

90

100

Sc

hw

a d

ura

tio

n, m

s

OCP

non-OCP

Exp 2: Results• Schwa deletion is quite common between the two

voiceless stops of Exp. 2.

• Such deletion is significantly positively correlated with being between two identical consonants (Pearson’s correlation coefficient=.07, two-tailed significance p=.058) .

% schwa present % schwa deleted Total N

OCP 76 23 241

non-OCP 69 31 477

Discussion

• An OCP effect on schwa duration is robust and replicable (even in the more prominent word-initial syllable).

• Schwas are longer between identical consonants than otherwise.

• Similarly, schwas are less likely to be deleted between identical consonants than otherwise.

Conclusions

• Even in the absence of categorical or grammaticalized repairs to OCP violations, speakers manipulate low-level acoustic variables in a gradient fashion in order to ameliorate them.

• Those documented here are phonetic counterparts to antigemination.

• This undermines claims that it is not a true OCP effect, and offers a potential diachronic origin for the phenomenon.