The purposes of ‘supporting the voice’ are to exercise control over the amount of air being expelled from the lungs during singing tasks and to maintain a steady flow of air (and thus create a steady singing tone).
The difference between how we breathe for singing and how we breathe for other daily activities lies not in the mechanisms but in how the airflow is regulated, as the demands that our bodies have for air changes with different activities. Although it is still in accordance with the natural functioning of the body, ‘natural breathing’ as employed for speech is not adequate for intense singing demands. During normal demands, such as speaking or resting, we tend to inhale and exhale more shallowly and evenly because our bodies don’t require as much oxygen. Air is exchanged in cycles of approximately four to six seconds; this differs slightly from person to person. During singing, however, we need to inhale quickly and often deeply, then exhale slowly and steadily, in a long breath, as we sing our phrases or notes.
Singing requires a higher rate of breath energy than speaking does, as well as the elongation of the breath cycle. The rate of expiration has to be retarded beyond that appropriate to speech, especially during passages or notes of durations greater than the normal ‘at rest’ breath cycle. This higher need for energy and stamina requires more muscle control and coordination in supporting the work of the diaphragm and the function of the larynx, and this is the part of breathing that needs to be developed through training. Learned controls must be mastered in order to enhance and extend breath management capabilities.
When it comes to supporting the tone of the voice, there are two schools of teaching: 1) a contracting of the abdominal muscles; and 2) an ‘inspiratory hold’ (appoggio).
Many contemporary methods of teaching encourage a contracting of the abdominal muscles. This technique involves utilizing the muscles of the abdominal wall to create an upward and inward force or pressure. The initial power of the voice is often loud (in part because the glottis tends to respond to the forceful air pressure by increasing its resistance, and pressing together more firmly and for longer during the closed phase of the breath cycle), but this power is not usually sustainable for very long. Attempting to support or ‘breathe from the belly (or diaphragm)’ like this creates a number of potential problems with how the breathing ‘engine’ and the larynx interact with each other. For example, rapidly pushing the abdominal wall inwards and upwards places pressure on the diaphragm, which then rises quickly and compresses the lungs, increasing the air pressure in the lungs. Air is forced out of the lungs rapidly, and through the glottis at a very forceful rate. The glottis then responds by either pressing the vocal folds together more firmly and for longer before sound is created (pressed phonation) or it blows apart and creates an airy or breathy tone.
In most classical singing schools, a technique called appoggio is taught. Appoggio requires support from the muscles involved in inhalation, rather than those responsible for forced expiration. Essentially, we delay, slow down and steadily pace the rise of the diaphragm by continuing to use the inspiratory muscles as we sing, which happens on the exhale. (This centuries old concept expressed by great teachers of the past such as Giovanni Battista Lamperti, is sometimes paraphrased ‘singing on the gesture of inhalation’.) During appoggio, we rely on the muscles of inspiration to help keep the diaphragm lower, in its position assumed during inhalation).
These muscles are primarily those that wrap around the ribs (the external intercostals and the interchondral part of the internal intercostal muscles). While the back muscles are contracting to maintain this ‘inspiratory hold’, the abdominal muscles must remain relaxed (thus the abdominal wall and lower ribs at the sides and back will remain expanded throughout most of the breath cycle). By ‘supporting’ with the inspiratory muscles, we keep the diaphragm lower and the lower ribcage expanded, which in turn creates lower subglottic pressure by maintaining the enlarged dimensions of the thoracic cavity. (It should be noted that some lower abdominal muscles are involved in initiating the airflow through the glottis, but the most important habit to avoid is the tendency to push the air out of the lungs by engaging and contracting or tightening the muscles of the abdominal wall. This will create too much subglottic pressure, an unsteady volume and tone and a rapid loss of air, and will lead to pressed phonation and potential vocal injury.)
Students of voice need to learn how to extend the normal breath cycle by remaining in the inspiratory position for as long as is both possible and comfortable, maintaining a raised sternum (but not raised shoulders or clavicle), avoiding displacement of the chest (or collapse of the ribcage), and allowing the muscles of the lateral abdominal wall to stay close to the position of inhalation. This vocal posture is often referred to as the ‘inspiratory hold’.
With the diaphragm kept in a lower position for longer, and with less air in the lungs to start out with, there will be less air pressure pushing on the vocal folds. Singers will notice that their endurance increases because they are no longer pushing the air out as rapidly. This will help them sing for longer on a single breath. It will also preserve their long term vocal health. Also, with more appropriate air pressure on the closed vocal folds during phonation, the tone will sound better – more rich and easy, and steady.
Credit: Article sourced from Singwise