The vibration of the vocal cords does not give rise to our single tone, instead an entire family or spectrum of tones is generated and these tones are called 'overtones'. Here, in the larynx, where we begin to sing, where we begin to speak, that vibration begins a channeling reaction of beautiful 'overtones' that can potentially be heard (J Sundberg 1987).
Therefore we could define the larynx as the first resonator (Pine 2003).
From there we continue going into the pharynx. The pharynx is usually considered a passage between the larynx and the nasal cavities (last and upper resonance chambers), and is actually divided into three different parts, anatomically speaking of laryngopharynx, oropharynx, nasopharynx, and it is here that our sound is enriched with harmonics.
A very important element in the oral cavity is the soft palate, which separates the oropharynx and nasopharynx, and even more important is that this component is free to rise, which is fundamental for the quality of the timbre of our voice.
And it is there that we must feel that we are 'carrying the sound', perceiving the passage into the superior resonators, concave bone structures that will enrich our sound as much as possible.
The mouth is considered a resonator but is often mistakenly thought of as the most important resonator. What happens in these cases is that you risk working in overdrive to try to put the sound out of the mouth to push the breath outwards, which involves using a lot of pressure in addition to the emission of a harsh sound.
What must be perceived is not the passage of air in the nasal cavities but their resonance and to ensure that this occurs, the sound must pass behind the soft palate, from the oral cavity to the nasopharynx, and the tongue must not push backwards, the path must remain free to allow the passage of air (Hanser 2010).
As we refine control and sensation at the level of the sensation palate and this is what we should be doing, the next step is refining the perception of resonance, the vibration of sound, moving through the vocal tract. It is a biunivocal sensitivity, the resonance in turn allows one to perceive the sensation of oneself in all the structures involved in the vocal tract. You can just feel it here or here and continue to work on a balanced feeling, on how the vibration is moving (Miller 1986).
The last resonator we have is not in the head, but it is the resonator of the chest, our chest. Here too it is very important that we leave the air, the sound, free to expand naturally, any respiratory forcing would be a control, therefore forcing by inserting rigidity into a mechanism that in itself is natural. The idea is to stop before the idea of sound itself, so as not to feel as if we were putting a bird in a cage but as if we wanted to let the structures vibrate to the best of their ability (Hansel 2010).
We need to think of all these structures as the architecture of a cathedral. If you walk inside a cathedral you realize that the sound is well balanced in every point we are in. This is allowed by the curvatures, by the architectural vaults. One of the advantages of a vaulted ceiling comes from the quality of resonance they induce. The resonance is strengthened and enhanced by the curved surfaces. According to the elementary laws of sound propagation and reflection, cylindrical and spherical surfaces not only concentrate and focus the sound, but also enhance and prolong the harmonics (overtones) of the original sound.
So, despite one's own vocal technique in singing and/or acting, it is very important that we allow these resonators to function in a natural way, in a relaxed way, in a way that is not pushed, not supported, precisely because the sound needs be absorbed and then reflected and due to the laws of materials, the lower the resistance, the greater the absorption and subsequent reflection (Reznikoff 2006).