The Pharynx and the Nasal Cavity are two resonating cavities that shape the sound produced by the Larynx.
Constricting the pharynx typically degrades the quality of the resonation. However, voice impersonators, like Rich Little, do amazing things by bring this resonator under voluntary control.
Others of us find an improved quality of voice when we learn to relax the muscles around the pharynx. Bing Crosby was probably the most relaxed man on earth when he sang.
The Nasal cavity is well known to anybody (everybody) who has had a head cold and has experienced the discomfort of having a stuffy nose. Try to say under those conditions the phrase ("Eminent Women.") It comes out ("Ebidedt Wobed").
Ironically, in English, there are only three sounds that use nasal resonance (i.e., are produced with the soft palate {velum} open.)
NOTES: So who is Rich Little?
NOTES: More on Rich Little.
NOTES: Want to hear some outstanding resonance?
NOTES: Some information on improvoving nasality if you want to spend big bucks.