1. Semi-Occluded Vocal Tract Exercises for Voice Therapy (and singing) AKA – Why we Trill, Hum, use straws etc.
Liz Savina, Redcliffe Hospital
For Qld Voice Special Interest Group
May 2014

2. Overview Definition & brief background of physics
What major therapy “programs” use it
Discuss some recent studies that show the effects of different parameters/ on different populations.
Demonstrations
Therapy hierarchies
Case examples

3. 3 Major Ways of Doing SOVT (Andrade 2014)
Constant frontal narrowing of the vocal tract (nasals/glides and hand-over-mouth);
Lengthening (and narrowing) the vocal tract through means of a tube (Lax-Vox/Straw).
Adding a 2ndry source of vibration into the vocal tract (lip and tongue-trills, Tube into water/fricatives).
Been used in various forms for over 100 years (Conroy et al. 2014)

4. My burning questions Is it guaranteed to work??
Which types are best for
building up vocalis (muscle within vocal cords) and closing glottic gaps versus
Improving retraction/deconstriction, preventing overclosure

5. Why/How Does SOVT Work?
Potentially decreases the aerodynamic power necessary for phonation & optimises closure of the vocal folds – neither breathy or pressed (Andrade et al )

6. An entire conference on SOVT!

7. A little bit of the physics
SOVT (at the lips) works by…….
Raising the mean supraglottal and intraglottal pressures
Impedance matching by vocal fold adduction and epilarynx tube narrowing can then make the voice more efficient and more economical (in terms of tissue collision).(Titze 2006)
Decrease in phonation threshold pressure Reduced minimum pressure at which the VC will vibrate
Decreased phonatory effort
Decreased strain
(Conroy et al 2014, Guzman et al., 2013),
The vocal fold adduction appears to be a reflex reaction.

8. A little bit of physics
Lowering of the first vocal tract formant (F1) allowing the fundamental frequency (F0) of speech to be closer to F1, Increasing inertive reactance of the vocal tract and producing a more efficient vocal fold vibration pattern -> easier voicing

9. Some SOVT
Widen the pharynx in relation to the epilarynx -> a clustering of the 3rd, 4th, & 5th formants (Andrade 2014) – “Singer’s Formant”

10. Marco Guzman, et al Resonance Tube and Straw Phonation 523.e27

11. SOVT is used in
Stemple’s Vocal Function Exercises (nasals & Finnish bilabial fricative)
Verdolini-Abbots – LMRVT – core part of her Voice Therapy Spectrum – using M
LaxVox (9mm id, 25cm (Andrade) or 35 cm (Stemple) tube in 1-5cm of water (aim for 3-5cm - Stemple)
Finnish Resonance Tube (soft silicone or glass tube cm & 9 mm id in 2-5cm of water or free air) ~40 year hx (Paes)

12. SOVT is used in Accent Method (voiced fricatives)
Estill Siren on “ng”, sirening
Titze’s Straw exercise (small diameter for men, larger diameter for women – Titze Brisbane 2013)
Glide loaded sentence of CAPE-V – We were away a year ago
& S/Z ratio

13. Lax Vox – Stemple 2011 1 of the Big 3 things for future voice therapy.

14. Lax Vox indicated for: Stemple (2011)
Holistic therapy for various functional and organic voice disorders:
Muscle tension dysphonia
Vocal fold nodules and polyps
Habitual and psychogenic dysphonias-aphonias (by masking proprioceptive feedback)
Vocal fold paralysis (RLN and SLN)
Presbyphonia
Puberphonia
• Pre and postoperative phonosurgery

15. Lax Vox in Singing and Theatre voice Stemple (2011)
Daily voice care for all groups of voice users
Prevention of voice problems for vocal athletes
Developing vocal muscles with several exercises (glissando, staccato, Messa di Voce, etc.)
Glottal closure deficiencies
Warming up and cooling down
Finding and developing the optimal voice (primal sound)
Balancing the glottal attack
Facilitating the lowered larynx
Developing registers and smoothing the passaggio
I find it interesting the Stemple has come out in such strong support of it, given he had his own SOVT exercises.

16. Lax Vox Reference
Denizoglu I, SihvoM. Lax Vox Voice Therapy Technique. CurrPractORL 2010, 6(2): (unable to find on Medline Ovid or Ebsco or Pubmed or even Google!)

17. SOVT researched in: Teachers (RVT and Finnish Tube)
Elderly (Finnish Tube)
Actors and singers (RVT)
“Behavioural” voice problems
Benign vocal lesions
Haven’t yet found research on Unilateral Vocal Fold Paralysis

18. Some Recent Studies

19. Some Recent Studies Immediate effects
normal speakers
trained/untrained instructed/non-instructed
dyshphonic/ hyperfunctional populations (tubes)
Effect of 6 week programme on “elderly” (tube in water)
24 Hours of RV

20. Summary of Articles will follow

21. Andrade et al 2014 Electroglottographic Study of Seven Semi-Occluded Exercises:…….Journal of Voice

22. Andrade 2014 SOVTE LaxVox (9mm id, 25cm –? Water depth)
Straw (12.5 cm in length & 4 mm in diameter)
Lip-trill
Tongue-trill
Hand-over-mouth
Humming
Tongue-trill with hand-over-mouth.
? Give demonstrations of each here?

23. Procedure Andrade 2014 N = 23 healthy volunteers
SP demonstrated and provided teaching on error until subjects produced correctly
Asked to do same pitch for all activities. Electroglottographic & Acoustic measures

24. F1 – F Andrade 2014
Use of SOVT significantly reduced the difference between The first formant and the Fundamental Frequency compared to a comfortable phonation of “ah”
You can see that for males and females there were different effects of the various SOVT, with the females gaining a greater reduction on Formant 1-Fundamental frequency. However there was a difference in the effect of the combination of tongue trill and handover mouth between males and females, suggesting the addition of the second source of vibration, while significant for both, might be more significant for females. LaxVox in males had the least reduction in F1-f0, while Tongue Trill in females had the least reduction in F1-F0

25. SOVTAndrade et al. 2014 Fluctuating (dual source) Tongue-trill
Lip-trill
LaxVox
with larger CQr &
F1 - F0 difference
More effortful phonation but ? gives massage effect
Steady
(single source)
Hand-over-mouth
Humming
Straw
with lower CQr & F1 - F0 difference
Easiest Phonation
Andrade proposed SOVT exercises should be separated into two groups. Those with a steady/single source of vibration – either narrowing or lengthening the vocal tract (with narrowing). These tend to lead to the easiest ohonation.

26. Massaging the Vocal Tract
Note the bouncing of the pharyngeal walls – easier to see in the second half of clip when the pitch is held constant.

27. Tongue Trill + Hand Over Mouth Andrade 2014
Exhibited mixed effects in both the exercise groups

28. Costa et al., 2011. Immediate effects of the phonation into a straw exercise

29. Costa et al 2011
N = 48, 23 with benign lesions (nodules, cysts, polyps, and Reinke’s edema ), 25 without.
Rigid plastic straw 8.7 cm long & 1.5 mm diam
Examiner demonstrated then participants did 1 minute of straw phonation at self selected mid range frequency and intensity.
Videolaryngoscopy, vocal self Ax, acoustic and auditory perception Ax

30. Costa et al 2011
Significant improvement on vocal self Ax in patients with benign vocal lesions (p=0. 015) but no change in patients without lesions.
No statistically significant differences before and after the exercise and between the groups, in the videolaryngoscopy, acoustic and auditory-perception assessments

31. Gaskill, C. S. , & Quinney, D. M. (2012)
Gaskill, C. S., & Quinney, D. M. (2012). The effect of resonance tubes on glottal contact quotient with and without task instruction: a comparison of trained and untrained voices. Journal of Voice

32. Gaskill & Quinney 2012 Two groups of male participants,
10 with no vocal training
10 with classical vocal training,
No instruction/practice: told keep pitch and loudness consistent
Instruction/practice: got to practice until found best pitch and loudness and had sense of oral resonance

33. Gaskill & Quinney 2012 Procedure
12 reps of a vowel-like phonation for at least 5 seconds.
Narrow glass tube, 8 mm ID and 50 cm
Some participants needed to be cued to not produce a humming or nasalized sound, but to allow all of the sound to go through the tube instead of coming through the nose.

34. Gaskill & Quinney 2012 Conclusions
Resonance tube can cause immediate and measurable changes in glottal CQ
These changes remain highly variable and do not always fit with theoretical predictions
does need an individualized approach that could include trying multiple tube lengths and diameters as well as extended and systematic practice with larger variations in pitch than those exhibited in this study

35. Guzman et al 2013 Laryngeal and Pharyngeal Activity During Semioccluded Vocal Tract Postures in Subjects Diagnosed With Hyperfunctional Dysphonia
8 SOVT exercises:

36. SOVT postures Guzman et al 2013
N=20 hyperfunctional dysphonia
8 SOVT exercises:
Blinded laryngologists rated 3 endoscopic variables using a five-point Likert scale
vertical laryngeal position (VLP), pharyngeal constriction, and laryngeal compression

37. SOVT postures in hyperfunctional dysphonia Guzman et al 2013
All semioccluded techniques produced
a lower larynx
narrower aryepiglottic opening
and a wider pharynx
Compared to resting position
VLP, A-P constriction,& pharyngeal width changed differently throughout the 8 semi-occluded postures.
Most prominent changes were obtained with a tube into the water and narrow tube into the air

38. Lower Laryngeal Position
Straw exercises: Before (left), during (middle), after (right)
Findings:
Lower laryngeal position both during and after
Higher velum position both during and after
Hypopharynx much wider during
(Different Guzman et al., 2013, pg 523.e24 Figure 6)

39. Paes, et al. (2013). Immediate effects of the Finnish resonance tube method on behavioral dysphonia. J Voice, 27(6), doi: /j.jvoice

40. Paes 2012
25 female teachers minimum 5-year history of dysphonia & no prior speech therapy.
Subjects produced 3 sets of 10 sustained phonations with a 1-minute rest between phonations
27-cm glass tube immersed in at least/up to 2 cm of water. 

41. Results – Paes 2012
68% of the teachers reported increased phonatory comfort
52% reported improved voice quality after performing the exercises.
Perceptual analysis: improved voice on counting numbers but not on “ah”
Spectrogram: decreased instability, subharmonics, noise in high frequencies, and the tendency for reduced low frequency noise on.
Mean fundamental frequency decreased.

42. Dos Santos, et. al.(2014). Verifying the effectiveness of using resonance tubes in voice therapy with elderly people.

43. Resonance Tubes in the “Elderly” Dos Santos et al 2014
Resonance Tube Group:
Improvement in Grade, Asthenia, Strain, Instability on GRBASI
No change in breathiness
90% self-reported improvement
Improved Vital Capacity
Improved spirometry

44. Resonance Tubes in the “Elderly” Dos Santos et al 2014
N= 42 elderly in long term care residential between ages of years
30 females
x6 1 hour weekly sessions of resonance tube, compared to vocal hygiene ed sessions.
Glass tubes (8 mm to 9 mm ID and 24 cm to 25 cm length in 2-5cm of water).
RT Therapy Rx: instructed to emit continuous sounds, nonsensical words, and to hum the tune of “Happy Birthday to You.”
Rest periods of up to two minutes between emissions.

45. Verdolini, 2012. Vocal exercise may attenuate acute vocal fold inflammation

46. Resonant voice for treatment of vocal fold inflammation Verdolini 2012
N=3 healthy males
Used Resonant Voice
Prospective, Randomized and double blind
1-hour vocal loading procedure, followed by randomization to a
Talking as normal condition, Vocal rest condition, RV exercise condition
Treatments were monitored in clinic for 4 hours and continued extra-clinically until the next morning.

47. Resonant voice for treatment of vocal fold inflammation Verdolini 2012
Results
Complete data sets were obtained for 3 inflammatory biomarkers--IL-1beta, IL-6, MMP-8
Results were poorest at 24-hour follow-up in the talking as normal condition
Sharply improved in the voice rest condition
Were the best in the RV condition

48. Summary
SOVT exercises can optimise the closure of the vocal folds, open the pharynx wider
These effects tend to occur immediately
They are not guaranteed to do so, so still need to be individually checked – person doing should feel a more “open throat”, less effortful voicing and sound should improve( that’s up to our subjective judgement)
If SOVT improves the vocal tract configuration, evidence shows this can then be carried over to vowels and other speech sounds.