1.4 Resonance subsystem of voicebuilding
The role of resonators in human vocal tract is played by a variety of respiratory tract cavities surrounding the vocal folds at the top and bottom. That's why they are divided into the upper and lower resonators. The lower ones are the trachea and bronchi. They give the voice resonance in the chest, fullness and volume.
The area above the vocal folds before the mouth is called the extension pipe or the vocal tract. It belongs to the upper resonators. These are the pharynx and the mouth cavity. The upper resonators, which also include the nasal cavity, are meant to amplify the voice built in the larynx, giving the sound the resonance in the head and significantly changing its sound.
Essential resonators are the pharynx and the mouth cavity. If you watch them under the X-rays, you'll see that while speaking and singing the shape of these cavities changes greatly, stretching out into narrow tubes and fissures and then expanding widely.
The nasal cavity unlike the vocal tract does not change its size and shape during speaking and singing, but, nevertheless, is involved in the formation of vowels and consonants, and can also influence the voice quality. This is possible due to the soft palate, which, depending on the activity of its high position, can adjust the degree of interaction between the nasal cavity with mouth and pharyngeal cavity.
The best conditions for optimal use of nasal cavity resonating properties are created with a slight distance between the palatine velum and the back of the soft palate.
In a normal position the soft palate hangs onto the pharyngeal cavity. In the middle of it there is a ledge, the uvula. The soft palate and especially the uvula are richly innervated and influence the muscle tone throughout the larynx. Therefore, the voice quality depends on the degree of the soft palate activity. The front of the soft palate transitions into the hard palate and its back goes down into two symmetrical folds of mucous membrane it's the palatopharyngeal arches. In their interior there are the muscles that lift the soft palate, and between the arches you can find the tonsils.
The hard palate and the soft one with labial incisors form the palatal arch, the structure of which also influence the tonal quality of the voice. The doctors notice that good singers have a highly symmetrical structure of the palatal arch.
Mouth cavity opens with a wide hole, the throat, from behind into the middle part of the pharynx. Good singers have their throat widened while singing.
The pharynx is a muscular tube ending with the arch of the skull in its top, and at the bottom it transforms, narrowing, into the throat in the front area and into the oesophagus in the back area. The volume of the throat may vary due to the reduction of its muscular walls of the larynx or its movement in the vertical direction as a whole.
Epiglottis, located in the lower part of the pharynx, also has the ability to change its position, which greatly influences the resonance of the sound.
You should keep in mind that the movement of the epiglottis generally depends on the vertical position of the larynx, the lower the larynx descends, the more inclines the epiglottis, covering the entrance to the larynx, and vice versa.
It is this complex movement that the veiled or open sounding depends on.
Thus, due to changes in volume and shape of the oral and pharyngeal resonators, their acoustic tuning changes, and a variety of vowels and consonants is produced. In addition, it is in the vocal tract that certain resonance conditions are created that determine the features of voice timbre.
About the head resonator
The phrase: "Sing to the mask" comes from the sensations in the area of the face. Among the head resonators only nasopharynx can change its size because of the mobility of the soft palate. The others remain still. High frequency overtones of the voice - such as a high singing formant around 3000 Hz - resonate in the sinus, whose length is about 3 cm. Radiograms of professional singers show that soft palate while singing separates the mouth from the nasopharyngeal cavity almost completely. When projected into the head resonator, singer's voice becomes fuller, and it is easier to sing for the singer himself. The voice is considered as well formed, if the sound resonates in the head. R.Yusson proved that while resonating in the head, the activity of laryngeal sphincter is stimulated, the work of what facilitates singing.
The techniques of "m-sound" or "n-sound" help to achieve your head resonator. Another exercise is singing a vowel with the singing formant of 400 Hz and 3000 Hz. Not all singers feel the head resonance in the same way. It all depends on the individual characteristics of the structure of vocal apparatus.
About breast resonating
In the men's voice the sensations of resonance in the chest persist for one octave and a half (up to falsetto), the female resonance is most developed in the chest register. The trachea is about 15 centimetres long, so its resonance frequency is of about 500 Hz. While resonating in the chest, the ligaments merge with their thickness. The voice gains low, velvety frequencies. The height of the tessitura that allows chest resonance depends on whether it is male or female voice, and of its type defined according to one of the classifications.
Professionally trained voice does have both resonances, in the chest as well as in the head, according to the principle "Put the head one on the chest one, and vice versa" (an expression of Italian vocal coach Camillo Everardi). The amount of low and high frequencies in the voice depends on the height of the voice tessitura and its type. For example, stronger female voices show the chest resonance more and retain it up to higher notes than this of lighter voices.