Articulation shapes the voice by filtering glottal sound through the vocal tract

Evidence

The wave from the glottis during phonation does not radiate directly out – it will propagate through the pharynx right above the larynx and then through the oral cavity above the tongue and possibly through the nasal cavity. These paths are called the vocal tract and the nasal tract. These acoustic tubes or cavities have an important impact on the final voice that radiates through the lips or the nostrils of a speaker. The process of controlling this acoustic process is called articulation. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 555

Categorization

• corroborated: 3 independent passages support this claim — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 555