1 Supralaryngeal Physiology

2 Introduction Source-filter theory –Source = generates sound (larynx) –Filter = sound modified (vocal tract) Vocal tract- –Filter for all vowels and consonants –Serves as source of noise for consonants

3 Noise Generation: Source All consonants include an element of noise (except semi-vowels) Consonant that is voiced= Noise added to the voice generated at Glottal Source Consonant that is voiceless= Characterized entirely by noise Narrowing of vocal tract causes resistance to cause noise (usually in upper vocal tract) –/h/ is an exception- noise caused at the glottis

4 Oral Pressure Two functions of vocal tract: –Serves as a filter for all consonants & vowels –Serves as a source of noise for most consonants Prerequisite for noise: –Build pressure behind constriction or occlusion Intraoral air pressure (requires velopharyngeal competence)

5 Turbulent Noise The noise element of consonants produced by fricatives is the result of turbulence. –Hiss of steam –Occurs when air channel is constricted enough to disrupt smooth flow of air –Turbulence if the other type of consonant noise (bursts & turbulence) –Place of articulation distinguishes fricatives

6 Places of Articulation H K-G-NG SH-ZH- L-CH-J-R T-D-S-Z-N TH M-W-P-B F-V

7 Bursts of Noise Burst, a puff of air Air stream is stopped by tongue or lips (plosive or stop) Progress of stop: –Closure (tongue, lips)-Block air stream –Pressure builds behind stoppage –Brief gap of silence –Stoppage is released (can be aspirated)

8 ClosureStoppage Release Transition Airstream Stoppage Transition Silence Plosive Burst Vowel Airstream Typical Plosive Production

9 Vowels Vowels studied using lateral head x-rays –liquid-barium Early description of vowels- –tongue height –tongue advancement –Russell & Leiberman- criticize theory (can’t distinguish /e/ and /  / by tongue contour only) –Must include: lip configuration height of larynx

10 Vowels Four features to describe vowels: 1) Tongue position 2) Lip configuration 3) Velar position 4) Width and length of pharynx

11 Vowels Characteristics: –all voiced –Sonorants (nonobstruent) Produced with relatively open vocal tract Voicing is dominant feature No blockage of airstream

12 Vowels Binary classification: –1) high/ low –2) front/ back

13 BEAT BITBIT BAIT BATBAT BOTTLE LOOT FOOT OMIT WALK LOTLOT LOTLOT LOOT Location of Vocal Tract Constrictions for Vowels

14 Glides & Liquids Referred to as semi-vowels or consonants –Greater degree of vocal tract constriction than vowels 1) Glides: articulatory movement connecting two vocalic type sounds –/j/: Tongue position for /i/ and rapid movement to next vowel more open vocal tract opposite of dipthong rapid movement important for distinction (two adjacent vowels) narrow constriction = turbulent flow

15 Glides & Liquids –/w/: same articulation shape as /u/, but more lip rounding and rapid articulation into following vowels (similar to dipthongs but faster articulation) 2) Liquids: –/r/: produced with some lip rounding context dependent usually assumes place of cluster its in (/sr/, /br/) palatal retroflex position

16 Glides & Liquids –/ l/: lateral sound tongue tip touches alveolar ridge openings on either side of tongue context sensitive differs greatly on position in utterance All glides have low flow (about 1/2 of vowels)

17 Entire class of Semi-Vowels Assume vocal tract is slightly more closed than for vowels Intraoral pressure slightly above atmospheric (about 1 cm/H 2 O) Translaryngeal flow will be less than vowels Lowest flow of any phoneme

18 Dipthongs Have flow similar to vowels (large) two vowel positions connected by slow tongue movement speed of articulation slower than glides articulatory posture different than producing separate vowels (ex. /aI/ not the same as /a/, /I/)

19 Consonants 1) Stops: –Characterized by: plosives (bilabial, lingu-alveolar, velar) voicing features (ex. /t/ vs. /d/) most complex set of sounds

20 Stops (plosives) Articulatory movement characteristics: –articulatory gesture towards intended articulatory place –contact of tongue or lips shutting off oral cavity –brief maintenance of oral occlusion ( msec) –release of occlusion

21 Stops 4 Specifications factors : 1) Closure interval (articulatory), build up of P o (aerodynamic), msecs 2) Release of constriction or burst (articulatory), P o drops to P atm (aerodynamic), 2-12 msecs

22 Stops 3) Expanding constriction (articulatory), turbulent flow & oral flow decs. (aerodynamic), 20 msecs (bilabials), (lingua-alveolar), (dorsals) 4) Closing vocal folds –folds open during closure interval –folds move to closed position for following vowel (same time as release) msecs –aspiration noise created (high flow & narrow fold opening)

23 Stops: Aerodynamics Consonant in medial position /ipi/: –upon contact P o rises steeply –cessation of flow –occlusion = stoppage of flow –after occlusion is released: P o falls steeply rapid burst of airflow

24 Stops: Aerodynamics Steps following the occlusive stage (voiceless): –no flow corresponding to occlusion –turbulent flow after release of articulators laminar flow becomes turbulent (narrow constriction)

25 Stops: Aerodynamics Burst- release of stop Frication- turbulent flow between expanding artic. constriction (“noise”) Aspiration- vf’s moving from open to closed; air moving past closing folds causes turbulence VOT Burst 2-12 msec Frication msec Aspiration 100 msec First vibration of folds

26 Stops: Aerodynamics Summary: Occlusion (no flow) Expanding constriction (turbulence) Narrow glottal chink (aspiration) 3 Stage Sequence of Stop Release

27 Stops: VOT Voiceless stop: –VOT= burst, frication and aspiration without vocal fold vibration Voiced stops: have shorter VOT, why? –no aspiration interval in voiced stops –just burst & frication –frication interval may also be shorter Aspiration does not occur during VF vibration flow not high enough because folds are moving & interrupting flow

28 Stops: Tense vs. Lax Voiced stops: –lax because of pharyngeal expansion –walls of vocal tract are very compliant –pressure increases, displace walls easier, thus decrease in pressure overall Voiceless stops: –tense; no pharyngeal wall expansion –pressure increased overall; less compliance

29 Fricatives Continuant consonants: –vocal tract constriction much greater than semi-vowels but no complete occlusion –created by narrow constriction somewhere in vocal tract –voiceless fricatives have higher P o than voiced –voiced fricatives less pressure than voiced stops

30 Fricatives voiceless: source supraglottal voiced: dual source (larynx and supraglottal) Aerodynamics: –1) very high P o –2) pressure held longer than plosives (cleft palate) –3) highest airflow (range cc/sec)

31 Affricates Composed of stop and fricative –brief occlusion interval (pressure high) –occlusion shorter than for stops (cluster duration shorter than single form) –Long frication interval (turbulent flow & slowly expanding constriction) –Flow and pressure in-between stops and fricatives

32 Nasals Oralization gesture= velum pulled up touching pharyngeal walls –seals oral cavity; build up P o –necessary for vowels too (lesser extent) Nasalization gesture= velum lowered –need resonance in nasal cavity –P o becomes negligible relative to P atm –V n and P n increase

33 Co-Articulation Articulatory movements for one phone which are carried over into the production of previous or subsequent phones, but which do not affect the primary place of articulation.

34 Co-Articulation Alot of overlap in running speech Theory: Speech series of beads (representing phonemes) presented in series: Not true Overtax muscular system Therefore, co-articulation occurs

35 Co-Articulation Kent, Carney & Severeid- –sagital X-ray motion –sutured metal pellets to velum & tongue –ex. /Int  nd/- forward and backward co-artic. after nasal /n/ velum moves well before closure for the /t/ closure starts at msec. before /t/ Right-to-left co-articulation: articulation gesture for upcoming phoneme occurs earlier in time

36 Co-Articulation Carryover: Left to right influences in which earlier phonetic activity replaces forthcoming phonetic activity Anticipatory: Right to left influences in which forthcoming phonetic activity replaces earlier phonetic activity

37 Co-Articulation Anticipatory: /stu/ –liprounding on /s/ –/s/ has no specifications for lip configuration Carryover : /no/ –vowel will be slightly nasalized because of lowered velum in production of /n/ –slower movements include VP opening & lip rounding

38 Organization of Speech Production Isolated production (ideal) CNS remembers appropriate ‘set’ of muscular activities to produce given phoneme there can be certain variations from ideal and still make sound appropriate perceptually Hypothesis of planning utterances

39 Organization of Speech Production Selection of craniofacial target forms associated with phonological unit selection of time program for speech –ex. /s/ in the words ‘speed’, ‘speedier’ & ‘speediest’ becomes shorter for each progression –evidence /s/ not independent of duration's of succeeding elements

40 Organization of Speech Production Organization of speech planning is roughly the length of a clause: 5-9 syllables in length Overall duration of these utterances is roughly constant regardless of # of syllables in a clause Therefore, the same phoneme changes in duration depending on what sounds surround it.

41 Organization of Speech Production Humans speak at close to maximum rates –6-7 syllables per second –10-14 sounds per second –We do fast movements with slow articulators by overlapping articulatory movements ex. difference in tongue position for “nine” and “ninth” –in ninth the tongue is fronted to adjust for the upcoming “th”

42 Quantal Theory of Articulation Certain point where undershoot or articulators for a phoneme will exceed the range of phoneme class Undershoot= failure of articulators to reach their craniofacial form Range of vocal tract configuration for prod. Outside range of variability= change in acoustic output Boundary creates quantum change

43 Quantal Theory of Articulation explains co-articulation with certain variability allowed