The position of the pharyngeal cavity

The human throat can be compared and contrasted to an acoustic guitar.


The important part is the components that are relevant to sound production, which are:

If the guitar is compared to the vocal organs:
1:Head=the cricothyroid muscle
2:Strings=the vocal cord
3:Body= the resonance chamber.

The body of the guitar is the most relevant to “making sound.” The material components and the structural composition decide the strength and quality of that sound.
‘The Book of Singing,’ states that, “the vocal cord is important but the resonance chamber is the most vital.”
The pharyngeal cavity’s role of sound production relies on the resonance chamber, the positioning, the ease of mobility and the space available.
The pharyngeal cavity is located behind the hyoid bone.
The following picture shows the hyoid bone(yellow) and the pharyngeal cavity(red) captured by a CT scan.


If the hyoid bone moves forward, the epiglottis is going to be able to stand vertically very easily. Which assists in making the space of the pharyngeal cavity maximally open, which is commonly referred to as, “opening the throat.”
You cannot expel or produce a good voice unless the hyoid bone is easily moved. Moving it smooth and easily will in turn create less stress to the area.
You should always refrain from opening your throat forcibly. Furthermore, the wrong way when opening your throat is pulling down your tongue quickly and with too much strength. The parts of the oral cavity and pharyngeal cavity can become enlarged with this way, and will harden the tongue and muscles around larynx. When this hardening occurs you will lose flexibility of the tongue and muscles around larynx, which I do not recommend.
I would like you to achieve and produce a high quality voice, using flexible movements of the pharyngeal cavity.

Note:Red circle is the epiglottis in the above photo.