1	VOCOLOGY: The Science and Practice of Voice Habilitation (A Vision for Utah) Ingo R. Titze, Ph.D. Director, National Center for Voice and Speech Distinguished Professor Speech Pathology and Audiology and the School of Music University of Iowa
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3	20-25% of the U.S. workforce use voice as a primary tool of trade Teachers Counselors Telephone workers Agents Receptionists Lawyers Ministers, etc. Actors, Singers
4	Voice Habilitation for teachers, singers, and other heavy voice users
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7	The Problem –Overexposure to tissue vibration, resulting in Nodules Polyps Chronic edema Vascular hemorrhages Vocal fatigue
8	Two Fundamentally Different Types of Vocal Fatigue Muscle fatigue Lamina propria material fatigue
9	Risk Factors for Lamina Propria Fatigue Vibration over-dose Lack of recovery time Poor tissue environment Genetically weak tissue structure
10	Genetics Factors Thickness of mucosa Toughness of skin (epithelial cells), basement membrane, and extracellular matrix Proteoglycan (liquid) composition Vocal fold geometry (length, thickness, left-right symmetry, etc)
11	Poor Tissue Environment Dehydration Smoke, chemicals, pollens Drugs Inadequate Nutrition Reflux
12	Vibration Dose Depends on Amplitude of vibration Frequency of vibration Duration of vibration
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17	Vibration dose criteria derived from industrial tool use (Griffin,1990) For hand-transmitted vibration Continuous exposure Based on “white finger” and “numbness of hands” responses
18	Safety limits for hand-transmitted vibration (Griffin, 1990)
19	Maximum Vocal Vibrational Doses Less than 17 minutes of continuous vibration Less than 100,000 cycles of continuous vibration Less than 0.5 joule/cm3 of continuous energy dissipation into heat Less than 0.5 km distance traveled in a cyclic pattern
20	How do we study vibration exposure? Understand the mechanism of recovery Build recovery times into vocal dose criteria Design auto-perceptive ratings of fatigue and recovery Test the exposure and recovery model on tissue in vitro and on human subjects
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22	Recovery times SHORT TERM restore circulation restore water to tissue remove lactic acid replenish calcium LONG TERM repair extracellular matrix repair blood vessels grow epithelial cells repair basement membrane
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25	Use of “Inability to produce soft high voice” (IPSV)as a means of testing lamina propria fatigue /hi-hi-hi-hi-hi/ Pitch glides “Happy Birthday” song
26	Inability to produce soft voice (IPSV) rating scale Currently a 1-10 point rating scale Higher values reflect voice breaks, delay of voice onset, lack of low intensity The speaker rates himself (autoperception)
27	Some hypotheses about IPSV Vocal warm-up reduces IPSV in proportion to the length of silence prior to phonation Adaptation to vocal warm-up is quick (0-1 hour) and the benefit lasts on the order of 5-10 hours Lamina propria fatigue increases IPSV in proportion to the short-term accumulated vocal dose, with a lag-time of 48-72 hours
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29	Vocal exercises that are known to produce results
30	Group 1: Semi-occluded vocal tract exercises Lip trills tongue trills lip-tongue trills (raspberry, or razz) bilabial fricatives humming phonation into thin straws
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32	What semi-occluded vocal tract exercises accomplish They maintain a positive supraglottal pressure to keep the vocal folds slightly abducted under high lung pressures They “square-up” the vocal folds vertically They lower the threshold pressure to get vibration started They allow pitch and lung pressure to be raised to high levels without excessive vocal fold collision
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36	Group 2: Staccato exercises Repeated notes, different rhythmic patterns Different speeds, including diadochokinesis Triads and arpeggios Mixes and matches of pitch , rhythm, and speed
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38	What staccato exercises accomplish They build strength, speed, and accuracy of vocal fold posturing They establish a clean onset of a dominant mode of vibration They facilitate superposition of small breath group modulations over an otherwise steady breath support They can be used as precursors to trillo and rapid accents in coloratura singing
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41	Group 3: Messa di voce exercises Crescendo-decrescendo in mixed registration only Crescendo-decrescendo with breathy onset and offset Crescendo-decrescendo at higher pitches with a closed vowel like /u/
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43	What messa di voce exercises accomplish They recruit tissue layers gradually into vibration and require the vocalist to match tension across the layers (ligament and muscle) They coordinate CT muscle activity, TA muscle activity, and lung pressure to maintain a constant pitch with variable loudness
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47	Group 4: Pitch glide exercises Descending pitch only, falsetto register Descending pitch only, falsetto register to mixed register Descending-ascending pitch, register balanced Ascending-descending pitch, register balanced
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49	What pitch glide exercises accomplish They gradually turn on the CT muscle while turning off the TA muscle, and vice versa (differential muscle control) By thinking down when singing up, they help to keep the larynx from ascending By resisting the use of excessive lung pressure when changing pitch , they prevent transient vibrational modes They allow seamless register changes to occur
50	Group 5: yawn-twang exercises Twang-creak combination for voice onset Yawn-sigh combination for voice onset
51	Rules for modifying voice quality Lowering larynx will lower all formant frequencies (longer vocal tract) Lip rounding will lower all formant frequencies Pharynx widening will lower F1 (yawn); pharynx narrowing will raise F1 (twang) Lip spreading and/or jaw lowering will raise F1
52	Vocal Ring has wide pharynx and narrow epilarynx tube ; it is the combination of twang and yawn
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54	What yawn-twang exercises accomplish They allow control over voice quality They help position the laryngeal vestibule for maximum vocal ring in the epilarynx tube (a tweeter boost) They can lengthen the vocal tract (acoustically) by coupling energy into the trachea (a woofer boost) They widen the pharynx for an additional woofer boost
55	Group 6: Phonation-articulation independence exercises Tongue rolls (waves, curls) Tongue extensions and retractions Jaw opening and closing Etc.
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57	What phonation-articulation independence exercises accomplish Keep larynx from moving vertically with articulation Keep vocal fold vibration from being perturbed
58	Group 7: Shriek exercises Uvular scrape Ary-epiglottal scrape Loud falsetto Falsetto-scrape combinations
59	Song or Shriek In the animal world, sound-making tends to be either song-like or shriek-like In song-like vocalization, the emphasis is on melody and the sounds are nearly periodic In shriek-like vocalization, the emphasis is on rhythm and the sounds are mostly aperiodic The degree of nonlinearity in tissue dynamics, aerodynamics, and acoustics determines whether peridicity or aperiodicity rules Many animals can “linearize” or “non-linearize” their sound production systems to sing or shriek
60	A Vision for Utah Build strong multi-disciplinary voice teams Remain neophytes- never stop learning. When we attain stature, we become statues. Attend the Summer Vocology Institute Keep America singing – follow the Sweden model Support local performing arts
61	The End