alicia beckford wassink * richard wright * lisa galvin * amber franklin †

Intraspeaker variability in vowel production: An investigation of motherese, hyperspeech, and Lombard speech in Jamaican speakers

Alicia Beckford Wassink *Richard Wright *

Lisa Galvin *Amber Franklin †

University of Washington, Seattle, [email protected] Linguistics Colloquium

17 October, 2003* Department of Linguistics† Speech and Hearing Sciences

funded by a grant from the Center for Mind, Brain and Learning, University of Washington

0.0 IntroductionPurpose: Characterize and compare several acoustic phonetic

parameters associated with so-called “perturbed” speech

Extend knowledge regarding the sources of systematic variability in speech --The Lombard effect and sociolinguistics

studies of audience design and “attention paid to speech” (Mahl 1975; Labov, 1984; Bell, 1984) have been influenced by investigations into auditor effects and speakers’ ability to self-monitor

1960’s (Labov): the notion of formality lies on a simple dimension of attention paid to speech

“formality” or “style”as a discrete variable, rather than a continuous one: WORD LIST > MINIMAL PAIRS > READING > INTERVIEW > CASUAL

Bell argues that we need a construct that does not confuse the code with factors influencing the code...”Language doesn’t covary with style. Style is an axis of its own.” (1984)

1.0 Background: Types of Exaggerated Speech Child-directed speech (“CDS”, Kuhl et al. 1997):

Speech directed to infant auditors is produced with a higher fundamental frequency, exaggerated pitch range, and slower rate of speech

more expanded F1 x F2 vowel space (92% larger than ADS) Question: Do adult speakers of a duration contrasting language show

stretching of cues crucial to phonemic contrast? Do hyperarticulated vowels facilitate the child’s category development?

The Lombard reflex (Lane & Tranel, 1971) Speech in which intensity is adjusted to compensate for changes in

background noise. An informational response. Question: Does the Lombard reflex affect parameters other than intensity?

Hyperspeech (“The Hyperspace Effect”, Johnson et al. 1993) Talkers modify F1 and F2 of phonetic targets in an effort to alleviate

perceived difficulties on the part of the listener in recovering information in the signal. An informational response.

e.g., corrective behavior, clarification of the content of an intended utterance (to another native-speaking adult addressee)

1.1 Goals of this talk Goal 1: Characterize the effects of four task types on key

phonetic parameters associated with vowel contrast.

Research Question 1: Do these four task types differ in the pressures they exert on key phonetic parameters?a.) F1 (Hz) c.) duration (sec) e.) intensity (dB)b.) F2 (Hz) d.) f0 (Hz)

Goal 2: Characterize cross-lectal similarities and differences in exaggeration strategies.

Research Question 2: Are the phonetic parameters exaggerated differently in a linguistic variety that employs spectral differences for vowel contrast than in another which relies upon temporal differences for signaling contrast?a.) Jamaican acrolect (spectral) c.) future: American English (spectral)b.) Jamaican basilect (temporal)

Vowels

--Vowels are sociolinguistic markers in Jamaican

American English: 1.2:1

1.2 Acrolectal and Basilectal Segmental Inventories

Long Short Diphthong L:Sbasilect (13)

/i˘, a˘, u˘/ /i, e, a, o, u/ /ie, ai, uo, ou/ 1.7:1

acrolect (16)

/i˘, e˘, a˘, ´˘, ç˘, o˘, u˘/

/i, e, a, o, ç, u/

/ai, çi, ou/ 1.5:1

2.0 Methods 1 A. Materials and

Equipment1.) 6 vowels in 3 tense-lax pairs:

acrolectbasilect

Heedie~Hiddie /i˘ / ~ /I/ /i˘/ ~ / i/ Haughdie~Haddie /ç˘ / ~ /a/ /a˘/

~ / a/Whoodie~Hoodie/u˘ / ~ /U/ /u˘/ ~ /u/

2.) Critters and critter cards3.) Tascam DA-P14.) 2 Shure WL184 supercardioid lavalier

microphones5.) Shure UT4 wireless bodypack

transmitter/receiver6.) Digital tape of white noise - 40dB noise

(Lombard task only) delivered over closed circumaural headphones (Sennheiser HD280)

2.1 Methods 2 B. Tasks and Amounts of DataFour randomized tasks (semi-crossed design):

unscripted/ child/ noise/scripted adult no noise

(Spontaneous-Adult) (unscripted) (adult) (no noise)(Familiarization)Spontaneous-Playtime (CDS) unscripted child both (12)Wordlist in carrier (CDS) scripted child both (24)Map (Hyperspeech)-corrective scripted adult both (24)Map (Hyperspeech)-noncorrective scripted adult both (24)

SubjectsTwo groups of 10 mothers/group (of infants 6-9 months of age). Data for 5

mothers/group are considered here.-- basilect: 5 mothers x 6 vowels x +/-84 tokens = 2520-- acrolect: 5 mothers x 6 vowels x +/- 84 tokens = 2520

2.2 Methods 3 C. Analysis1.) digitized at an 44kHz sampling rate2.) downsampled to 11.025kHz for analysis in Praat 4.043.) overall measures: duration4.) midpoint measures: f0, F1, F2, F3 (in Hz), intensity (dB)5.) f0 range for each speaker6.) Inter-measurer reliability (10%) = 91%7.) Inferential Statistics: Factorial MANOVA (4 x 2 x 2 x 2 design)

--Appropriate post-hoc comparisons--Independent variables (discrete): Task (4 levels), Group (2 levels), Noise (2 levels) and Auditor (2 levels)--Dependent variables (continuous): f0, F1, F2, intensity, duration--Speaker (within subject factor)

3.0 Summary of Results Research Question 1 (restated): Do these four task types

differ in the pressures they exert on key phonetic parameters?By-parameter results

1.) Intensity: the Lombard task shows the highest dB values. CDS means not significantly different from Lombard.2.) f0: mothers show the widest ranges in CDS and Lombard tasks

Research Question 2 (restated): Are the phonetic parameters exaggerated differently in a linguistic variety that employs spectral differences for vowel contrast than in another which relies upon temporal differences for signaling contrast?By-group results:1.) Region: Main effect of region on vowel duration (p<0.01)2.) F1: Main effect of region on F1 (p<0.01)3.) F2: Main effect of region on F2 (p<0.03)

3.1 Results: by Phonetic TaskTable 1: Mean values for 5 phonetic parameters, by task (* indicates a statistically significant difference at p<0.05)

Task duration (sec) F0 (Hz) intensity (dB)High Front Low High BackHigh Front Low High Back

Baseline 0.1187 102.6249 - 465.0535 478 836 465 2569 1533 998 63.8(stdev) 0.0415 range=362.4 92 117 76 317 315 209 7.9

* *

CDS 0.1290 122.7013 - 492.2706 457 860 488 2544 1472 1005 66.80.0665 range=369.6 87 98 101 461 252 233 9.5

* * * *

Lombard 0.1268 104.5526 - 492.2706 475 865 495 2538 1428 999 67.20.0679 range=387.7 79 103 100 431 239 208 8.8

* * *

Hyperspeech 0.1217 128.6723 - 426.8028 484 874 484 2511 1450 994 64.40.0509 range=298.1 90 128 79 407 299 235 8.3

* * * * *

ParameterF1 (Hz) F2 (Hz)


F1xF2 dispersion - By Task (category means)

400450500550600650700750800850900

8001000120014001600180020002200240026002800F2 (Hz)

F1 (Hz)

Baseline

CDS



400450500550600650700750800850900

8001000120014001600180020002200240026002800F2 (Hz)

F1 (Hz)

Baseline

CDS

Lombard



400450500550600650700750800850900

8001000120014001600180020002200240026002800F2 (Hz)

F1 (Hz)

Baseline

CDS

Lombard

Hyperspeech

3.2 Results: by Group (Acrolect vs. Basilect)Table 2: Between-group differences for 5 phonetic parameters. (* indicates a statistically significant difference at p<0.05). Means for F1, F2 are computed using distance scores for tense vs. lax vowels (e.g.,( F1Bas/i:/-F1Bas/I/)-(F1Acr/i:/-F1Acr/I/)).

Task duration (sec) F0 (Hz) intensity (dB)High Front Low High BackHigh Front Low High Back

CDS -0.011 -18.94 21.66 10.91 80.96 -103.65 30.13 254.95 11n.s n.s * n.s. * * n.s. * *

Lombard 0 -49.75 6.02 17.90 73.59 113.88 244.19 173.87 8(CDS excl.) n.s. * n.s. n.s. * * * * *

Hyperspeech -0.010 -53.62 138.59 144.40 51.67 192.27 394.31 446.65 6n.s. * * * * * * * n.s.

ParameterF1 (Hz) F2 (Hz)

3.2 Results: by Group (Acrolect vs. Basilect)Table 2: Between-group differences for 5 phonetic parameters. (* indicates a statistically significant difference at p<0.05). Means for F1, F2 are computed using distance scores for tense vs. lax vowels (e.g.,( F1Bas/i:/-F1Bas/I/)-(F1Acr/i:/-F1Acr/I/)).

F1xF2 dispersion - By Group (Acrolect category means)

300

400

500

600

700

800

900

70010001300160019002200250028003100F2 (Hz)

F1 (Hz)

Baseline

CDS

Lombard

Hyperspeech

F1xF2 dispersion - By Group (Basilect category means)

300

400

500

600

700

800

900

70010001300160019002200250028003100F2 (Hz)

F1 (Hz)

Baseline

CDS

Lombard

Hyperspeech

4.0 DiscussionRegister Theory, a more integrated view:“Variation on the style dimension within the speech of a single

speaker derives from and echoes the variation which exists between speakers on the “social” dimension.” (Bell, 1984:151)

Present study suggests that it is most profitable to consider “style” as an axis. Linguistic features are used as resources available to the speaker from the set available in social variation. The speaker chooses among available features (which comprise variables) as they design speech for a particular audience, based upon their perception of that speaker’s:

linguistic experience (competence in target language) environmental experience (noise) social features (age) discourse context (attitude toward the topic, conversational

factors)

4.0 DiscussionAudience Design Theory, Bell 1984:“Variation on the style dimension within the speech of a single


LINGUISTICVARIATIONLINGUISTICEXTRA-LINGUISTICPhonologicalSyntactic...Interspeaker

“social”Intra-speaker

“stylistic”ClassAgeNetwork...AttentionAddresseeTopic...LINGUISTIC

4.0 DiscussionAudience Design Theory, Bell 1984:“Variation on the style dimension within the speech of a single


LINGUISTICVARIATIONLINGUISTICEXTRA-LINGUISTICPhonologicalSyntactic...Interspeaker

“social”Intra-speaker

“stylistic”ClassAgeNetwork...AttentionAddresseeTopic...LINGUISTICMICROSTYLE(Sociolinguistics)MACROSTYLE(Discourse Analysis,Ethnography of speaking)

4.0 DiscussionExamination of a single set of phonetic parameters across several exaggerated speech tasks has yielded:

A rich database for inquiries into intra-speaker variability A more sophisticated understanding of phonetic differences that

obtain between different types of “exaggerated speech”. A larger pool of languages for which CDS has been examined (i.e.,

new data from a creole language), and further clarified differences between two varieties of this language.

Results with implications for language acquisition: ‘Do speakers emphasize those dimensions that will be crucial for the child’s phonemic category development?’ If between-group durational differences disappear under CDS, but spectral differences remain, are spectral differences of particular importance in category development? Not necessarily. Both emphasize durational differences in tense~lax contrast.

ReferencesBell, A. (1984) “Language style as audience design.” Language and Society (13).

Cambridge: Cambridge.Crothers, J. (1978) "Typology and universals in vowel systems." In Universals of

Human Language (J. H. Greenberg, C. A. Ferguson and E. A. Moravcsik, eds.). Stanford: Stanford UP, 93-152.

Johnson, K., Flemming, E., & Wright, R. (1993) The hyperspace effect: Phonetic targets are hyperarticulated. Language, 69 (3), (505-528).

Kuhl, P. K., Andruski, J. E., Chistovich, I. A., Chistovich, L. A., Kozhevnikova, E. V., Ryskina, V. L., Stolyarova, E. I., Sundberg, U. & Lacerda, F. (1997) Cross-Language Analysis of Phonetic Units in Language Addressed to infants, Science (277), 684-686, Aug 1.

Labov, W. (1984) “Field Methods of the Project on Linguistic Change and Variation.” In, Language in Use, (J. Baugh and J. Sherzer, editors). Englewood Cliffs: Prentice-Hall.

Lane, H., Tranel, B. & Sisson, C. (1970) Regulation of Voice Communication by Sensory Dynamics, Journal of the Acoustical Society of America, 47(2), 618-624.

Lane, H., & Tranel, B. (1971). The Lombard sign and the role of hearing in speech. Journal of Speech and Hearing Research, 14, 677-709.

Lehiste, I. (1970) Suprasegmentals. Cambridge, Mass.: MIT, 18-33.Mahl, (1975)Snow, C. E. & Ferguson, C. A. (1997, eds.) Talking to Children: Language Input and

Acquisition. Cambridge: Cambridge UP, 31-49.Wassink, A. B. (2002) Theme and Variation in Jamaican Vowels, Language Variation and

Change 13(2).

alicia beckford wassink * richard wright * lisa galvin * amber franklin †

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