The sound should seem to be formed, not in the throat,--thus involving the vocal cords,--but in the resonance chambers.
THE EPIGLOTTIS The epiglottis is the valve which closes over the upper opening of the larynx.

It not only closes the mouth of the larynx when food is swallowed, but aids materially in converting into tone the vibrations set up by the vocal cords.
THE PHARYNX The pharynx extends from the larynx to the nasal cavity.

The size of the opening into the nasal chamber is controlled by the soft palate and is frequently entirely closed.

The size of the pharynx is varied by the contraction and relaxation of the circular muscles in its tissue; when swallowing its walls are in contact.

The pharynx acts as does the expanding tube of brass instruments.