First, it’s good to understand how little we understand and that there are no simple answers. Ingo Titze’s Principles of Voice Production book has proven this to me several times. Before I thought that Bernoulli effect explains the vocal fold vibration. However, Titze (2000, 88-89) writes that it cannot explain the vibration by itself. A small thing like vocal folds and their function are such complicated subjects that their proper understanding requires a lot of study. I have to read same chapters again and again. Every time I understand a little bit more. Does it help me to sing better? Not at all! How about teaching? Perhaps. It’s useful to know how things work. Broader understanding feeds creativity and development of new teaching methods. However, you won’t find straightforward answers in books. Or if you do they are usually half truths or speculations.
Vocal production can be divided into three parts. Lungs (power), vocal folds (source) and vocal tract (filter). Air flowing out of the lungs makes the vocal folds vibrate which creates sound. Vocal tract amplifies and filters that sound. However, the process is not quite linear. All parts of the system have an effect on other parts. For example, the vocal tract can affect the vocal folds' function and the phonation threshold pressure (Titze & Verdolini Abbott 2012, 286-310).
So what should you know about the vocal folds? I think it’s useful to understand at least that the faster the vocal folds vibrate the higher the pitch. It’s good to know something about the structure of the folds and know they attach to cartilages that move in various ways. I think it’s not that essential to remember which muscle moves which part of the larynx. It’s quite enough if you understand that these parts need to be able to move into different positions. One setting or muscle tension can work for one pitch or sound quality and yet it can be totally wrong and unhealthy for another. There might very well be individual variations and different strategies to produce similar sound qualities.
Many might have heard about CT (cricothyroid) and TA (thyroarytenoid) dominance when talking about registers. To put it simple the idea is that head voice/falsetto/M2 is CT dominant and chest voice/M1 is TA dominant. In order to change smoothly between registers we should increase the activity of one and decrease the activity of the other. Does this help with singing or teaching? I don’t think so. Furthermore it’s wrong! The activity of CT seems to be dependent on the pitch not the register (see Kochis-Jennings 2008 & Hull 2013).
How about muscles of breathing? It could be useful to have a look at the anatomy book in order to get an idea what kind of muscles there are in the torso. Many singers have an incorrect idea about diaphragm so I guess it’s good to know where it is and where it’s attached. It’s more essential to understand how breathing works and what kind of role the diaphragm plays in it. It doesn’t help the singer to sing any better if they know all the latin names of those muscles. And instead of muscles teacher should know the meaning of pressure differences in breathing.
Knowing how the tongue and the jaw move can be helpful in understanding the acoustics of the vocal tract. Personally I don’t remember that many names of the muscles but I know how different parts move. I also know what kind of shapes it is possible to make with the vocal tract. Anyway, concentrating on how a single muscle works is a bad practice strategy. Or have you heard that anyone would have learnt to walk by focusing on their thigh muscles? It’s more important to have an understanding of the acoustics of the vocal tract. You should know the basics of overtones, formants and resonances and understand their function in singing.
Overall, when it comes to details of how our body works I think it’s important to remember what is their function in voice production. The whole is more important than the details. In my earlier blog post I wrote about breathing. It doesn’t matter much how you produce an even sublottic pressure as long as you do it. Of course, in teaching we are usually looking for the least effortful way. I guess the main point of my writing(s) is that there is a lot of information out there and very few things are straightforward. There are conflicting views so the more you read the more you learn to be critical. Eventually that will prove to be useful for both teaching and singing.
Hull, Darcey Marie (2013). Thyroarytenoid and cricothyroid muscular activity in vocal register control. University of Iowa.
Kochis-Jennings, Karen Ann (2008). Intrinsic laryngeal muscle activity and vocal fold adduction patterns in female vocal registers: chest, chestmix, and headmix. University of Iowa.
Titze, Ingo (2000). Principles of Voice Production. Iowa City: National Center for Voice and Speech.
Titze, Ingo & Verdolini Abbott, Katherine (2012). Vocology - The Science and Practice of Voice Habilitation. Iowa City: National Center for Voice and Speech
After my last blog post I got a question about support and breathing so I thought I could write a bit more about it. First a disclaimer: I'm trying to balance between being specific and clear so probably I will fail miserably in both.
We all know that air flowing out of the lungs is needed for the vocal folds to start vibrating (of course you could produce sound by inhaling too but let's leave that out for now). In order to keep the vocal folds vibrating the airflow must be kept up. Phonation threshold pressure (PTP) is the minimum subglottic pressure needed to keep the vocal folds vibrating. If the pressure stays under the threshold there is no vibration. PTP is affected by the fundamental frequency and also the amount of adduction and stiffness of the vocal folds as well as the shape of the vocal tract (see eg Titze 2000).
In singing the PTP is changing constantly. So the suitable pressure to make different sounds is changing. Let’s make it a bit more simple and think what happens if we produce one long tone in one pitch without changing the quality. We need both a constant subglottic pressure and vocal fold setting. Because the air is flowing out while we sing the lung volume diminishes too. You can perceive that around chest and abdomen. Singers have been observed to have different strategies on whether the chest or the abdomen goes in first. Anyway it’s simply not possible to keep them both extended while singing a phrase. The pressure would drop too low.
It doesn’t matter much how exactly you produce the necessary pressure as long as you do it. Because singers are different there are probably many viable training strategies. There are two that I advice to avoid though. First one is trying to keep the whole torso expanded which will lead to insufficient pressure. The other one to avoid is to tense muscles suddenly. That will often lead to subglottic pressure first increasing and then decreasing which will probably have an effect on the sound quality and pitch.
Things that are utter nonsense can work as learning tools for singers. I come up with all kinds of images when I’m teaching. Often they prove to be useful. However, I always remind that they are just that, images. They don’t represent how things actually work. So even if I said earlier that you shouldn’t keep your torso expanded thinking about doing it might actually work in some cases.
While on the subject I’ll give a little critique on how support is presented in Complete Vocal Technique. Cathrine Sadolin describes support as if holding back the breath (Sadolin 2018). The idea is that after we have inhaled our lungs want to let the air out. We should work against this urge by engaging our abdominal and back muscles. I guess this could be true in theory if we would only sing until our lungs reach their resting volume. You can find your resting lung volume by inhaling and then letting your breath out with a relaxed sigh. You will find that it is possible to exhale even after that. In order to do that we need to engage our abdominal muscles. Those muscles Sadolin describes as support muscles (which would mean that according to her they hold back the breath).
I believe that the muscles of both inhalation and exhalation should work together from the beginning of a phrase so that we can better regulate the subglottic pressure. More intensive phonation and higher fundamental frequency require higher subglottic pressure. PTP is higher and vocal folds won’t vibrate if the pressure stays too low. I find it pretty logical that muscles of exhalation can assist in controlling the pressure.
So what is holding back the breath if not support muscles? That is vocal folds (adduction and stiffness I mentioned earlier). For this reason I think it’s useful to include vocal fold function when training “support”. In practice this could mean doing the same exercise several times and changing the focus between laryngeal function and support muscles.
So PTP is changing depending on the pitch and intensity. This means that also the intensity of the muscle work to produce the pressure is changing. I believe that if there is an option of achieving the artistic expression with smaller pressure change you should aim for that. I have some interesting observations about this, one from the study I did together with Johan Sundberg (Sundberg et al 2017). However, I’ll write more about them later.
This post got a bit too long as it is but I’m happy to continue discussing the subject in the comments. Next weekend I’ll be heading to London to attend the conference ‘Towards Best Practice: Teaching Singing in Higher Education’. I’m going to write a more in-depth post about it later but you can tune into my Facebook and Instagram for some real-time updates.
― Ville ―
Sadolin C. (2018). Complete Vocal Technique mobile application. Complete Vocal Institute.
Sundberg J., Holmberg A., Bitelli M., Laaksonen V. (2017). The "Overdrive" Mode in the "Complete Vocal Technique": A Preliminary Study. Journal of Voice.
Titze I. (2000). Principles of Voice Production. Iowa City: National Center for Voice and Speech.
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