Many beginners are understandably concerned about vocal strain, especially if they notice a sudden deterioration in their singing ability following attempts to sing high notes or distortion or some similarly challenging vocal task. However, there are a lot of misconceptions about vocal strain, and these have the overall effect of associating singing with fear and, ironically, increase the amount of straining going on.
In order to know what we are talking about, it is helpful to first construct a working definition of strain. Unfortunately, the word "strain" is itself a complicated matter because it conflates at least two different phenomena, whose definitions are given here:
Strain as elastic deformation due to stress, something that happens to the vocal folds and is prone to causing microscopic tearing and subsequent vocal injury.
Strain in the sense of straining for high notes, ie. the felt need to rely on excessive effort to ascend in pitch.
To disambiguate them, we shall refer to only the former as 'strain' and the latter as 'pushing'. These two phenomena are obviously related, but they are not the same. For example, the first thing to understand about strain is that all voice usage comes with some amount of strain. The degree to which this will cause long-term vocal damage depends however on a variety of factors such as the duration and severity of strain as well as how quickly you recover. What is fine to do for a person who eats heartily, exercises, and gets plenty of rest may not be fine for someone who is eating at a caloric deficit, sleep deprived, and dealing with a concurrent illness. This means that there is no one-size-fits-all answer regarding what is safe to do with your voice and what is not.
We can however establish certain trends. For example, a physics equation from Ingo Titze's Principles of Voice Production explains that strain is proportional to pitch and amplitude. This fact may go a long way in explaining why so many clients of laryngologists are operatic sopranos, but it has also led to a tendency among some speech-language pathologists to caution people to avoid loud volumes, especially at high pitches.
In practice, this tends to cause patients to simply "curb" their voices more, ie. restrain the sound not by decreasing the intensity of the vibrations in the larynx, but merely by making the transfer of energy less efficient. The biomechanical and acoustical aspects of how this is done are beyond the scope of this post, but they will be addressed in future blog posts. For now, it is sufficient to observe that it is possible to reduce the volume without actually decreasing the pressure acting on the vocal folds or the amplitude of their vibration.
Understanding strain
To properly understand the causes of straining and their remedies, it is helpful to dig a little deeper into the working definition given earlier. Firstly, elastic deformation simply refers to a temporary change in the shape of an elastic material, like when stretching a rubber band. Stretching your vocal folds — as in mixed voice — is an example of strain in this sense, as is the wavy movement your vocal folds make when vibrating. Fortunately, vocal folds are quite elastic and are very capable of withstanding this type of strain. Had this not been the case, singing would not be possible.
Far greater strain can however result from chaotic movements in which microscopic spots on your vocal folds are displaced relative to neighbouring spots, causing microscopic strain that can far exceed that caused by ordinary singing. It is this type of strain that is prone to causing tearing and inflammation that can eventually build up to a persistent issue.
There are two main causes of such chaotic shearing forces: pressed phonation and breathy phonation. Pressed phonation involves squeezing the vocal folds together, which increases the friction between them, whereas breathy phonation involves an excess of air between the vocal folds that becomes turbulent.
Does this mean that all breathy singing should be avoided? No. While breathy singing does tend to involve higher airflow than clear singing, it is not necessarily the case that the turbulence heard as breathiness arises inside the larynx in all cases of breathy singing. Airflow can theoretically become turbulent as it passes through the vocal tract, though the extent to which this happens is not clear. However, even supposing that all breathy singing involves turbulent airflow in the larynx, this does not mean it needs to be avoided. A normal healthy individual can withstand some amount of vocal strain provided they get enough rest to recover. As a general rule, if it feels fine, and there are no apparent signs of deterioration, it is probably fine.
If there is one lesson I wish to impart about breathy phonation, it is this: breathiness is turbulent airflow, and at loud volumes, this turbulence becomes a violent turbulence, like a tiny storm inside your throat. It is for this reason that Complete Vocal Technique cautions against breathiness specifically at loud volumes. Shouting, for example, which is known in CVT as Overdrive, should be bold and clear rather than breathy.
Pressed phonation is not as much of a culprit as breathy phonation, but here too a greater intensity will tend to mean more strain. However, since pressed phonation is often associated with reductions in volume, you cannot use volume as a guide for estimating the strain caused by pressed phonation. Instead, it is to a large extent the degree of pressing that determines the amount of strain. In case your ears are not trained to easily identify the amount of strain, you can loosely estimate it by comparing the volume of a sound to the amount of effort ("support") required to produce it. For example, if you are expending a lot of effort to produce a sound of modest loudness, it is probably — but not certain to be — because of pressing.
So far however I have not found pressed phonation to be a major culprit when helping students with vocal health problems, and in fact pressing can be a useful tool to provide some safety margin against falling into the opposing pattern of excessive airflow. Manuel Garcia, the inventor of laryngoscopy, himself advocated the Valsalva manoeuvre — an extreme type of pressing — as a useful last resort for addressing excessive breathiness.
A culture of fear
Many voice teachers put a very great emphasis on vocal health and inspire fear in their students with horror stories of various vocal injuries and subsequent botched surgeries. From a commercial point of view, this serves two important functions. For one thing, it makes the students averse to experimenting on their own and thus sustains their dependence on the teacher. Secondly, it provides a handy excuse in case the student wants to learn a technique that the teacher is not capable of performing and does not know how to teach: simply call it unhealthy and urge the student to stay away from it.
This can easily become part of a whole array of control tactics such as coming up with intangible standards of correct technique that are unintelligible to the student, or alternating between subtly contradictory instructions belonging to different vocal techniques. For example, teachers may alternate between instructing students to breathe low into the back and instructing them to maintain an upright posture. These instructions are incompatible because breathing in the back requires some degree of slouching. Thus, as soon as students do the one correctly, the teacher can simply pivot to the other instruction and keep the student running in circles.
I am not suggesting that such voice teachers are conscious of using these tactics in their practice, but manipulative behaviours have a tendency to disguise themselves as sincere concern even to the person engaged in them.
Worse still, instilling fear of vocal damage can lead to a timidity that hinders the singer's sense of freedom and ease. The singer may for example hold back the volume out of a belief that loud singing is inherently unhealthy, and by far the easiest way to reduce the volume is simply to make the whole vocal mechanism less acoustically efficient by messing up the coordination in various ways. Obviously, this does not reduce straining, nor does it constitute a path to effortless singing.
The hazards of shouting
There is a widespread misconception that singing loudly, using wide vowels, or taking chest voice high in pitch will inevitably lead to vocal damage. We have already seen one reason why this is untrue: singers differ in their recovery speeds and general health, and there is no clear line to draw between damaging and non-damaging behaviours, only quantitative assessments of differing amounts of strain. However, of all vocal myths known to me, this is perhaps the most persistent, pernicious, and unfounded, so it will serve us well to address it in detail.
Firstly, it should be understood that our vocal tracts act essentially like a horn that transfers sound from our comparatively small vocal folds to the comparatively large outside air. For this reason, the vocal tract has a narrow end near the vocal folds, and this end is made even narrower in loud singing. Likewise, loud singing tends to feature a large mouth opening so as to better transfer the sound to the outside air. While there are many valid reasons to use a smaller mouth opening — faster articulation, access to close vowels, greater facility with quieter volumes — acoustic efficiency is not among them.
Secondly, while the detractors of chest voice generally associate it with pressed phonation and a muffled timbre, this need not at all be the case. A well-coordinated chest voice will have a brassy, blaring timbre (CVT Edge) or an open, spacious timbre (CVT Overdrive), and will be capable of very loud volumes at much less effort than would be required to achieve similar volumes in other coordinations.
As for pressed phonation, it is actually needed in moderate quantities not in chest voice but in the most popular approach to mixed voice. In more technical terms, as the vocal folds stretch and thin, an increased amount of medial compression becomes needed in order to maintain the glottal closure and avoid flipping into falsetto.
When people habituated to chest voice struggle with close vowels, quiet volumes, or high pitches, the problem is not an excess of facility with chest voice — as if there could be such a thing as an excess of facility with a vocal coordination — the problem is rather a lack of facility with other coordinations, be it mixed voice or falsetto, or some other coordination. To maximise technical versatility and range of expressiveness, a singer must master both chest voice and mixed voice.
Summary
All singing involves some strain. The key to maintaining a healthy voice is to make sure you're recovering faster than you're deteriorating. Since people differ in their recovery speeds and duration of performance, there is no one true answer to which coordinations are safe and which are not.
Loud volumes are not inherently damaging, and trying to hold back the volume is a major reason for strain in a lot of singers.
Breathy singing consists of turbulent air that will, at loud volumes, become a violent turbulence like a tiny storm in your throat. Therefore, avoid using a breathy tone when singing loudly.
A voice teacher keeping you in chronic fear of vocal strain is a major red flag.
Fear and timidity are antithetical to free, effortless singing.
Chest voice is not inherently damaging, but like all vocal techniques, it has its own strengths and limitations. Therefore it is important to develop facility with both chest voice and mixed voice.