Long or short?
Wide or narrow?
Deep or shallow?
And do they target different things?
Straw Semi Occluded Vocal Tract Exercises (SOVTE) work off a pressure-flow relationship and are guided by the principles of fluid dynamics. This relationship creates static back pressure
Why is back pressure good for singers and voice users?
Back pressure from straw SOVTEs helps to reduce the collision between the vocal folds; bringing them together gently, whilst concurrently preventing less air from escaping (Titze, 2006; Titze et. al., 2002).
It also helps widen the pharynx (back of the throat) and produce a louder voice without an increase in vocal effort (Laukkanen, Horáček, Krupa & Švec, 2012).
Which straws do what?
Straws used for SOVTEs vary in length, diameter and depth (if using water), which modifies the physiological and acoustic effects of the exercise. Here is what each SOVTE straw variable achieves:
- LONGER STRAW
= more back pressure
- SMALLER DIAMETER STRAW
= more back pressure
- DEEPER SUBMERSION INTO WATER
= more back pressure, increased oral pressure
How can I modify back pressure?
As you just read, both increased length and small diameter straws increase back pressure. But if you want to change the back pressure quickly, reach for a smaller diameter straw over a longer straw.
A comprehensive study by Andrade et. al. (2016), on straw diameter, length and submersion for SOVTEs showed that doubling the length of a straw from 5cm to 10cm only had a small effect on back pressure, whereas changing to a smaller diameter straw instead, had a more dramatic effect on back pressure.
So, which one should you use?
If you only want a small shift in back pressure, opt for changing the length of your regular diameter straw, rather than changing diameter.
If you want a big change, switch out your regular length straw for one with a smaller diameter.
Who typically uses large diameter straws?
Patients with hyperfunctional and hypofunctional voice disorders and singers wanting to relieve their throat of tension
Clinicians can help target motor learning which focuses on slow, sequential, specific positioning tasks. The greater sensory feedback from a larger diameter straw allows the user to detect errors easier and adjust their movement to better target their rehabilitative goal.
Who typically uses small diameter straws?
Professional singers and people learning to sing
The large changes in back pressure by smaller diameter straws may be better suited for singers who need to increase their awareness of their interplay between respiration, phonation and resonance.
It may also be a useful tool for helping singers reach higher pitches
(Titze et. al., 2002)
Considerations for SOVT straw exercises
For wider tubes in water, the main decisive factor for back pressure is the water depth
For thin tubes in air, the decisive factor for back pressure is the air flow.
This means that your recommendations for straw diameter, length and depth will result in different effects on the vocal apparatus for the user. This is where it is important you are crystal clear on both the physiological effects of your recommendations and the goal you are working toward with your student or yourself. This is so you can customise exercises for individual goals.
You don’t want to be promising greater vocal athleticism and giving an exercise for rehabilitation instead. Whoops!
Andrade, P. A., Wistbacka, G., Larsson, H., Södersten, M., Hammarberg, B., Simberg, S. & Granqvist, S. (2016). The flow and pressure relationships in different tubes commonly used for semi-occluded vocal tract exercises. Journal of Voice, 30(1), 36-41.
Adams, J. A. (1971). A closed-loop theory of motor learning. Journal of motor behavior, 3(2), 111-150.
Enflo, L. (2013). Collision Threshold Pressure: A novel measure of voice function Effects of vocal warm-up, vocal loading and resonance tube phonation in water (Doctoral dissertation, Linköping University Electronic Press).
Granqvist, S., Simberg, S., Hertegård, S., Holmqvist, S., Larsson, H., Lindestad, P. Å. & Hammarberg, B. (2015). Resonance tube phonation in water: High-speed imaging, electroglottographic and oral pressure observations of vocal fold vibrations-a pilot study. Logopedics Phoniatrics Vocology, 40(3), 113-121.
Laukkanen, A. M., Horáček, J., Krupa, P., & Švec, J. G. (2012). The effect of phonation into a straw on the vocal tract adjustments and formant frequencies. A preliminary MRI study on a single subject completed with acoustic results. Biomedical Signal Processing and Control, 7(1), 50-57.
Maxfield, L., Titze, I., Hunter, E., & Kapsner-Smith, M. (2015). Intraoral pressures produced by thirteen semi-occluded vocal tract gestures. Logopedics Phoniatrics Vocology, 40(2), 86-92.
Radolf, V., Laukkanen, A. M., Horacek, J., Vesely, J., & Liu, D. (2013). In vivo measurements of air pressure, vocal folds vibration and acoustic characteristics of phonation into a straw and a resonance tube used in vocal exercising. In Proceedings of the 19th International Conference Engineering Mechanics, Czech Republic (pp. 478-483).
Simberg, S. & Laine, A. (2007) The resonance tube method in voice therapy: description and practical implementations. Logopedics Phoniatrics Vocology 32, pp. 165-170.
Titze, I. R. (2006). Voice training and therapy with a semi-occluded vocal tract: rationale and scientific underpinnings
Titze, I.R., Finnegan, E.M., Laukkanen, A-M. & Jaiswal, S. (2002) Raising lung pressure and pitch in vocal warm-ups: The use of flow-resistance straws. Journal of Singing 58, pp. 329-338.