- (phonetics) Portion of the human body where speech sounds are articulated; the oral cavity, nasal cavity, and pharynx.
- 1858, George Murray Humphry, “The Skull”, in A Treatise on the Human Skeleton (including the joints), →OCLC, page 220:
- The vocal tract. The further office which the nose performs, namely, that of contributing to the proper modulation of the voice, depends in great measure on the various cavities and sinuses contiguous to the nasal fossæ.
- 2001, Michael Dobrovolsky, “Phonetics: The Sounds of Language”, in William O'Grady, John Archibald, Mark Aronoff, Janie Rees-Miller, editors, Contemporary Linguistics, →ISBN, page 18:
- ...the tube of the throat between the larynx and the oral cavity, which is called the pharynx; the oral cavity; and the nasal cavity. These passages are collectively known as the vocal tract.
- (ornithology) Portion of a bird's anatomy that filters or modifies sound; the syrinx, oral cavity, and beak, plus portions of the esophagus and trachea.
- 1998, Abbot Gaunt, Stephen Nowicki, “Sound Production in Birds: Acoustics and Physiology Revisited”, in Steven Hopp, Michael Owren, Christopher Evans, editors, Animal Acoustic Communication: Sound Analysis and Research Methods, →ISBN, page 308:
- Beak motions are not necessarily the only means by which birds might vary the acoustic properties of the vocal tract.