an ultrasound study of the trough effect in vhv sequences natalia zharkova queen margaret university...

An ultrasound study of the trough effect in VhV sequences

Natalia Zharkova

Queen Margaret University College,

Speech and Hearing Sciences

[email protected]

Ultrafest III, Arizona 16 April 2005

Triggered by: 1. Recent research on troughs in VCV

sequences like /aba/

2. What we know about /h/:

/h/ /h/ is unspecified for tongue position (e.g. Keating

1988, Pierrehumbert & Talkin 1992, Ladefoged 2001, Karbownicki 2004)

/h/ is also unspecified for lip and jaw position…

/h/ has a lot of freedom for coarticulation

Troughs A “trough”, or a lowering of the tongue, has

been found in bilabial consonants surrounded by identical vowels (e.g. Houde 1967, Gay 1974, Gay & Ushijima 1974, Bell-Berti & Harris 1974, Engstrand 1988, Svirsky et al. 1997, Lindblom et al. 2002, Fuchs et al. 2004, Vazquez Alvarez, Hewlett & Zharkova 2004)

Bilabial consonants, like /h/, are considered unspecified for a particular tongue position

So:

interesting to see what happens when /h/, which is even more unspecified than bilabials, is between two identical vowels

Questions: What would be the pattern of tongue

behaviour during VhVs? Specifically: Does the tongue maintain the same position

throughout the VhV sequence? If not – what differences occur? E.g. is there a trough on /h/? Is the V1

position different from the V2 position?

Data collection QMUC ultrasound system three native British English speakers data = /ihi/, /uhu/, /aha/ carrier phrase “I said … too”

(“eehee”, “oohoo”, “aha”) sixteen times each

Creating three annotations: mid /h/, V1, V2

Analysis

mid V1 mid /h/ same distance /h/ - V2

Creating three splines – V1, /h/, V2:

Analysis

splines superimposed on each other:

Analysis

Typical tongue contours during /uhu/

mid V1

mid V2

mid C

1. Comparing occurrence of different tongue shape patterns

Analysis

Distances along vertical measure bar:

V1 – C C – V2

V1

V2

/h/

2. Measuring tongue movements throughout VhVs

extracting xy spline coordinates from US analysis software

importing xy values into Matlab

3. Comparing whole contour shapes

Black solid line –V1

Red solid line –/h/

Blue dashed line – V2

Typical tongue shape pattern during /uhu/

Calculating the distance from each point on the C curve to its nearest neighbour on the V1 curve and separately on the V2 curve

Plotting these distances

Distances between V1, C and V2 curves


Black solid line –V1 Red solid line – /h/


Results

1. Comparing occurrence of different tongue shape patterns

Trough (highest point of C below both VV) Antitrough (highest point of C above both VV) Neutral (highest point of C between two VV)

Tongue shape patterns distribution by vowel

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

i u a

Trough

Neutral

Antitrough

Results

2. Distances of tongue movement throughout VhVs

Distances of tongue movement

Very small

distances

!!!!!!!!!!!!

aha ihi

uhu

Error Bars show Mean +/- 1,0 SD

Bars show Means

-1,0

-0,5

0,0

0,5

1,0

dis

tan

ce

, mm

first second

-1,0

-0,5

0,0

0,5

1,0

dis

tan

ce

, mm

aha ihi

uhu

Error Bars show Mean +/- 1,0 SD

Bars show Means

-1,0

-0,5

0,0

0,5

1,0

dis

tan

ce

, mm

first second

-1,0

-0,5

0,0

0,5

1,0

dis

tan

ce

, mm

Significant differences in tongue displacement sizes –

no significant differences in tongue displacement sizes –

/i/ vs /u/

/a/ vs /i/,

/a/ vs /u/

3. Comparison of whole contour shapes

tongue contours, by vowel…

Results

Average tongue shape pattern during /ihi/


Red solid line –/h/ Blue dashed line –

V2

Average tongue shape pattern during /ihi/

Distances between V1, C and V2 curves, /ihi/

V1 /h/ V2Middle part of the tongue typically lowers during the consonant

!“Trough”!

Distances between V1, C and V2 curves, /ihi/

Back part of the tongue on average moves slightly backwards during the consonant

V1 /h/ V2

!Relaxation of Advanced Tongue Root!

Average tongue shape pattern during /uhu/




Average tongue shape pattern during /uhu/

Distances between V1, C and V2 curves, /uhu/

V1 /h/ V2Middle part of the tongue typically lowers during the consonant

!“Trough”!

Distances between V1, C and V2 curves, /uhu/

Tongue typically goes backwards from V1 into C, and forwards again for V2

V1 /h/ V2

!Relaxation of Advanced Tongue Root!

Average tongue shape pattern during /aha/




Average tongue shape pattern during /aha/

/aha/

One obvious and rather consistent pattern:

/aha/

/aha/

/aha/

/aha//aha/ /aha/

Distances between V1, C and V2 curves, /aha/

Front part of the tongue is on average lower for V2 than for V1

V1 /h/ V2

!Second syllable stressed!

/aha/ fewer number of troughs and their

significantly smaller size in /a/ than in the other two vowels

possible explanation:

for the open vowel /a/ raising, rather than lowering, would be expected during tongue deactivation (Lindblom et al. 2002, Vazquez Alvarez, Hewlett & Zharkova 2004)

/aha/

/aha//aha/

/aha/ /aha/ /aha/


ihi

aha

V1 /h/ V2

uhu

Differences between V1 and V2 On average V1 is further away from C than V2,

suggesting a syllable boundary influence and showing asymmetrical nature of VCV:

ihi uhu aha

V1-C: 0,539 0,582 0,362

V2-C: 0,387 0,519 0,310

Conclusions Tongue is in a very similar position for both

vowels and /h/ However, there is some evidence that /h/ is

more like V2 than like V1: a syllable boundary effect

Some evidence for troughs, but they are small

More troughs in /i/ and /u/ contexts than in /a/ context

Troughs/antitroughs mainly occur in mid and back parts of the tongue

Front of the tongue – continuous movement from V1 to V2

Conclusions

Implications for the future Why these patterns? May be some properties of /h/ May be due to syllable boundary within the

VhV sequence May be due to stress position and its

physical characteristics

… Future research…..

Bell-Berti, F. & Harris, K.S. (1974). More on the motor organization of speech gestures. Haskins Labs. Status Rep. Speech Res., SR-37/38, pp. 73-77.

Engstrand, O. (1988). Articulatory correlates of stress and speaking rate in Swedish VCV utterances. Journal of the Acoustical Society of America, 83, pp. 1863-1875.

Fuchs, S., Hoole, P., Brunner, J. & Inoue, M. (2004). The trough effect – an aerodynamic phenomenon? [Oral presentation, “From Sound to Sense”, 11-13 June 2004, MIT.]

Gay, T. (1974). Some electromyographic measures of coarticulation in VCV utterances. Haskins Labs. Status Rep. Speech Res., SR-44, pp. 137-145.

Gay, T. & Ushijima, T. (1974). Effect of speaking rate on stop consonant-vowel articulation. Speech Commun. Semin., Stockh., SCS-74, pp. 205-208.

Houde, R.A. (1967). A study of tongue motion during selected speech sounds. PhD diss. Speech Commun. Res. Lab., Santa Barbara, Monogr. No. 2.

Karbownicki, L. (2004). Investigation of the coarticulation effects on [h] when preceding a vowel. BSc, Honours project, Queen Margaret University College.

Keating, P.A. (1988). Underspecification in phonetics. Phonology 5.2, pp. 275-292.

REFERENCES

Kozhevnikov, V.A. & Chistovich, L.A. (1965). Rech: Artikulyatsiya i vospriyatiye (Speech: Articulation and perception). Moscow-Leningrad. Translation: Kozhevnikov, V.A. & Chistovich, L.A. (1965). Speech: Articulation and perception, No. 30, p. 543 (Joint Pub. Res. Service, Washington).

Ladefoged, P. (2001). A Course in Phonetics. 4th edn. Orlando, FL: Harcourt College Publishers.

Lindblom, B., Sussman, H.M., Modaressi, G. & Burlingame, E. (2002). The trough effect: Implications for speech motor programming. Phonetica, 59, pp. 245-262.

Perkell, J. (1986). Coarticulation strategies: preliminary implications of a detailed analysis of lower lip protrusion movements. Speech Communication, 5, pp. 47-68.

Pierrehumbert, J. & Talkin, D. (1992). Lenition of [h] and glottal stop. In J. Docherty & D.R. Ladd (eds.), Papers in Laboratory Phonology II: Gesture, Segment, Prosody. Cambridge: Cambridge University Press. Pp. 90-117.

Svirsky, M., Stevens, K., Matthies, M., Manzella, J., Perkell, J. & Wilhelms-Tricarico, R. (1997). Tongue surface displacement during bilabial stops. Journal of the Acoustical Society of America, 102, pp. 562-571.

Vazquez Alvarez, Y., Hewlett, N., & Zharkova, N. (2004). An ultrasound study of the "Trough Effect". [Poster at the British Association of Academic Phoneticians Colloquium 2004, University of Cambridge, Cambridge, UK.]

REFERENCES

an ultrasound study of the trough effect in vhv sequences natalia zharkova queen margaret university...

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