
The vocal tract is the cavity in human beings and in animals where sound that is produced at the sound source (larynx in mammals; syrinx in birds) is filtered. In birds it consists of the trachea, the syrinx, the oral cavity, the upper part of the esophagus, and the beak. In mammals it consists of the laryngeal cavity, the pharynx, the oral cavity...
Found on
http://en.wikipedia.org/wiki/Vocal_tract

the passages from the glottis through the nose and throat that influence the quality of the voice.
Found on
http://www.encyclo.co.uk/local/21001

Type: Term Definitions: 1. the air passages above the glottis (including the pharynx, oral and nasal cavities, and the paranasal sinuses) that contribute to the quality of the voice.
Found on
http://www.medilexicon.com/medicaldictionary.php?t=93034
No exact match found.