Voice physiology
The voice, also known as phonation, is the result of several steps carried out by organs, muscles and bone structures. It could be defined as the sound produced when the air is exiting the larynx, which makes the vocal cords vibrate, but it is something more complex than that.
The following systems are used when singing:
1) phonation system
2) respiratory system
3) resonance chamber
Voice is a natural instrument we all possess that encompasses three qualities:
1) Timbre
2) Tessitura
3) Intensity
These three qualities are limited to the physical characteristics of each human being. The tessitura (italian word for texture - general range of pitches found in a melody or vocal part) is determined by the length and mass of the resonance chamber - larger the chamber, the lower or deeper the voice of the singer (the vibrational frequency of such chamber will be lower).
On the contrary, the larger the vibrational frequency, the higher-pitched voice and smaller the resonance chamber.
Once the sound is emitted from the larynx, it resonates in the chest, throat, and/or vocal resonators. The intensity and timbre of the voice depends on the resonance, the way the vocal cords vibrate and the use of the resonators for each vocal range.
The respiratory system is the place where the air is stored, it is divided into two parts:
1) The lower tract - starts in the trachea and ends in the lungs going through the bronchus, bronchioles and alveolus.
2) The upper tract - includes the nasal cavities, mouth, pharynx and larynx.
The vocal cords are located at the larynx, which is mainly cartilage; a small bone called hyoids which is surrounded by muscles.
The larynx is composed by nine muscles, and if we consider singing to be mainly a physical activity, we need to activate all these muscles before we launch them into the marathonic process of such activity. Only one of these muscles is in charge of closing the larynx, this is the respiratory muscle, and it should be the first one we need to activate during vocalisation. The other eight muscles are directly involved with phonation, hence their name, phonation muscles.
From there we go to the location of our air tank. The lungs are protected by the thoracic cage, which is linked to the vertebral column via the sternum. Just under the lungs we have the diaphragm where the lungs rest, when the diaphragm contracts the lungs expand, and the air comes into the body naturally, we do not have to think about lowering the diaphragm to breathe, otherwise we could suffocate and die if we didn’t pay attention or were asleep - these movements are completely involuntary. Once the air enters the lungs, the diaphragm relaxes and the lungs contract releasing the air.
It is important to emphasise that the diaphragm is an involuntary muscle, which means we aren’t required to control it. However, the muscles that we can control are the intercostal muscles, these help the ribs to move either, upward (“pigeon chest,” I made up this term) or to the sides (“toad’s back,” I also made up this term). When using these muscles, we then can control the size of the thoracic cavity and the intake and release of the air.
Vocalization is the simplification of the most basic forms of voice emission. We do this by controlling the emission, treating each part of the body we use when signing as a separate tool, and then adding different muscles with each exercise.
I will expand on Vocalisation on my next blog post.
This blog has been written by Yonora Guzmán Aguilar one of our I Have a Voice Choir Masters.
