550 likes | 740 Views
Aspects of speech production in typically-developing children . Laura L. Koenig Haskins Labs and LIU–Brooklyn. (non-exhaustive cast of characters). Some significant people. Karen Landahl. Richard Schwartz. Katherine Harris. Leigh Lisker. Richard McGowan. Arthur Abramson.
E N D
Aspects of speech production in typically-developing children Laura L. Koenig Haskins Labs and LIU–Brooklyn
(non-exhaustive cast of characters) Some significant people Karen Landahl Richard Schwartz Katherine Harris Leigh Lisker Richard McGowan Arthur Abramson Anders Löfqvist
1989: UPenn & Haskins • Photo credit to Philip Rubin • Leigh Lisker … Made a suggestion to • Arthur Abramson leading to …
Thursdays with Leigh and Arthur Lunch at the College Spa [“the trough”] Wendy in soundbooth B: The windowless guts of 270 Crown Street Lipton tea (courtesy Haskins) and Macintosh apples (courtesy Arthur) at midnight in the basement kitchen Bedtime: Signup sheets and room precedents
1991: CUNY & Haskins Thanks to Kathy for talking with me in soundbooth B... etc. Enter Anders and Richard
Airflow data: Papa Hopper Acoustics /h/ Airflow
Airflow data: Papa Sapper Acoustics Airflow /s/
Laryngeal coarticulation in adults Peak flow (l/m) Airflow data showing effects of vocal-fold abduction Löfqvist, Koenig & McGowan, 1995
Laryngeal control & Voice Onset Time • Lisker & Abramson (1964) • Timing of voicing relative to stop release • Serves to characterize stop distinctions across many languages • Googlescholar citations: 1579 • Subsequent transillumination studies (Lisker et al., 1969): Aspiration associated with abduction close to release. • Löfqvist (1992): VOT-peak abduction correlations pretty good but not perfect.
VOT in Development (1) V Developmental studies of voicing in stops Malcolm S. Preston, Grace Yeni-Komshian, Rachel E. Stark & Diane Kewley-Port Haskins Laboratories Status Report: SR-13/14 1 January 1968 - 30 June 1968
VOT in Development (2) V • KewleyPort & Preston (1974) (and others). • Hierarchy of “difficulty”: • Voiceless unaspirated [p t k] (short-lag) appear first (Jakobson) Subsequently: • Voiced [b d g]: Require aerodynamic control [more on this later] • Voiceless aspirated [phthkh]: Require timing control. • Assumption: Children have an established abduction gesture; all they need to do is time it correctly.
An aerodynamic study of consonantal voicing control in normal men, women, and 5-year-olds CUNY 1998 Katherine Harris Richard Schwartz Anders Löfqvist “Look at /h/” “Do something developmental”
VOTh* *A measure proposed by Richard McGowan, and it made some sense.
O T (E) V
Results (1): VOT and VOTh 100% Adult male Adult female 50% 0% 0% 50 ms 50 ms Koenig, 2000
VOT and VOTh (2) 5-year-old 100% 50% 0% 0% 100 ms Correlations for all speakers (N=21): VOTh x VOT /p/: r =.64* VOThx VOT /t/: r =.65* VOT /p/ x VOT /t/: r = .78* Koenig, 2000
/h/ profiles: Intraspeaker variability Koenig, 2000
Inconsistent abduction in children Koenig, 2000
Implications At 5 years of age, many children still have highly inconsistent laryngeal activity for /h/—where the only requirement is a laryngeal adjustment. If /h/ shows extreme variability in abduction extent and temporal patterns, it is sensible to infer similarly variable abduction gestures for /p t/ (probably more difficult; interarticulator coordination). VOT in development is not only about the timing of abduction.
3 more aerodynamic studies 1) Aerodynamic control in voiced stops 2) Laryngeal and supralaryngeal coordination in fricatives (including /h/); assessment of variability 3) Laryngeal coarticulation (following Löfqvist et al., 1995)
Methods for the 3 studies • 10 children 4–5, 9–10 years; 10 women /h s z p b/ in VCV contexts; 25-30 repetitions each
3 more aerodynamic studies 1) Aerodynamic control in voiced stops Laryngeal coarticulation (following Löfqvist et al., 1995 and Nittrouer et al., 1989) Laryngeal and supralaryngeal coordination in fricatives (including /h/) Recall: Kewley-Port & Preston: [b d g] appear later because of aerodynamic complications
Stop consonant voicing as “hard” Closing the upper vocal tract => intraoral pressure (Pio) builds up. Maintaining phonation requires a translaryngeal pressure drop across the vocal folds Adults perform compensatory maneuvers that slow Pio buildup; allow voicing to persist Obstruent devoicing is “phonetically natural”
Even harder in kids • Compared to adults, children have • Small supraglottalcavities • Vocal fold characteristics (stiffness, thickness, damping) that probably require higher transglottal pressures for phonation (cf. modeling work of Lucero & Koenig, 2005) • Past studies inferred that children have limited aerodynamic control in service of voicing, but no direct data comparing Pio and voicing in children.
Measuring Pio: Müller & Brown (1980) Measures of voicing and Pio in men AND Aerodynamic modeling Shape of Pio contour: Slow-rising contours as evidence of aerodynamic control(compensatory maneuvers)
Intraoral pressure signals: Papa Bopper acoustics flow pressure p p b
The dmeasure (Müller & Brown, 1980) • > 0: fast-rising (like /p/) d < 0: slow-rising (like /b/)
Results: Voicing Absolute: C * Age NS Age x C p=.07 Percent: C * Age NS Age x C * b p •Some evidence that voicing distinctions are less pronounced 5-year-olds than adults, as predicted from past work. Koenig & Lucero, 2008
Results: d C: * Age: p=.02 Age x C: p=.09 b p •Some evidence that adults show greater aero-dynamic differentiation than children. b p b Koenig & Lucero, 2008
Results: Pio differences related to voicing •Adults: All correlations significant and in expected direction. •Children less often significant, with some trends in the wrong direction. Clearer aerodynamic differen-tiation in adults. b p b p Koenig & Lucero, 2008
Implications •As predicted by Kewley-Port & Preston, and expected based on anatomical considerations, children do show less evidence of aerodynamic control of stop voicing than adults. In some cases, maybe even at 10 years of age.
3 more aerodynamic studies Aerodynamic control in voiced stops 2) Laryngeal and supralaryngeal coordination in fricatives (including /h/); assess variability Laryngeal coarticulation (following Löfqvist et al., 1995) High variability in development noted at least as early as 1969 (Eguchi & Hirsh).
Fricative development and production • Sibilants often considered “difficult” : late/variable in acquisition, frequently affected by residual speech-sound disorders, susceptible in motor speech disorders, etc. • Compare • /h/: VF abduction only • /z/: Tongue-tip constriction, min. abduction • /s/: VF abduction + TT constriction
/h/ and /s/ again •/h/: VF abduction •/s/: abduction + tongue tip constriction •measure VCV interval Koenig, Lucero, & Perlman, 2008
Functional Data Analysis Time-warp individual productions signals to bring peaks/valleys into better alignment Extent of warping required yields measure of temporal (or phasing) variability Remaining variability in aligned signals: Amplitude variability with timing factored out
FDA warping functions original /h/s amp. variab. vertically align warping SD time-align (warp) amp. SD resulting average Koenig, Lucero, & Perlman, 2008
Final FDA Output Average signals, ±1 SD Average warping and amplitude variability indices (one number per C)
Indices: Group averages s z s h z h Age * C * Age x C NS Age * C NS Age x C NS Koenig, Lucero, & Perlman, 2008
Indices: Individual data Koenig, Lucero, & Perlman, 2008
Sum: Articulatory specificity • Variability is comparable across consonants in some speakers... • But in others (adults as well as children) variability may be higher in the larynx OR the tongue tip. • “Difficulty” of /s/ is not all about lingual control: there’s also an issue of aerodynamic control. • Speaker-specific patterns of variability: Not just “noise in the system”
Individual variability patterns h≅s≅z 5yr Ad. Koenig, Lucero, & Perlman, 2008
Individual variability patterns s,z>h 5yr 10yr Koenig, Lucero, & Perlman, 2008
Individual variability patterns h,s>z 10yr 5yr Koenig, Lucero, & Perlman, 2008
Sum: Time and amp. variability • Control of amplitude (gestural magnitude) appears to mature earlier, in general, than temporal phasing. • cf (?) Ferguson and Farwell’s (1975) account of phonological variability in very young children: • –Ways to say ‘pen’: [pʰɪnbuãhɪndɛdṇmbõ] • •But Anders and colleagues find something different for lip data.
3 more aerodynamic studies Aerodynamic control in voiced stops Laryngeal and supralaryngeal coordination in fricatives (including /h/) Laryngeal coarticulation (following Löfqvist et al., 1995 and Nittrouer et al., 1989)
Coarticulation in development Do children coarticulate “more” than adults? Yes: Nittrouer et al. (1989); theoretical work by Studdert-Kennedy (1981) No: (Kuipers, 1993; Smith et al., 1996) All past studies evaluated supraglottal articulators
DC flow: One adult /h/ Similar to Löfqvist, Koenig & McGowan (1995) /p/ /b/ Koenig (2004)