An ultrasound study of the trough effect in VhV sequences Natalia Zharkova Queen Margaret University...
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Transcript of 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
Ultrafest III, Arizona 16 April 2005
/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
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
Distances between V1, C and V2 curves
Black solid line –V1 Red solid line – /h/
Blue dashed line – V2
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
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/
Average tongue shape pattern during /ihi/
Black solid line –V1
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/
Black solid line –V1
Red solid line –/h/
Blue dashed line – V2
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/
Black solid line –V1
Red solid line –/h/
Blue dashed line – V2
Average tongue shape pattern during /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/
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.]
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