Definition of "phonation"

Phonation. The voice is produced when the closed, taut vocal folds in the position of phonation are opened and made to vibrate by an air stream expelled from the lungs, causing sound waves to be produced. The volume of sound depends on the force of the air stream, and the pitch is determined by the frequency of vibration. The latter depends on the length (sex and age differences), tension and thickness of the vocal cords, as in the strings of a musical instrument.

1993, Werner Kahle, Helmut Leonhardt, Werner Platzer, Color Atlas and Textbook of Human Anatomy, Vol. 2: Internal Organs, 4th rev. edition, Stuttgart, New York, N.Y.: Thieme Medical Publishers, page 124

Voice teachers who emphasize relaxation are loath to use such words as 'pinch' or 'squeeze' in relation to singing. Catford and Laver, whose field is primarily the phonetics of speech rather than singing, both considered 'full glottal phonation' to be the 'normal' setting for speech as well as for the falsetto voice […] . They advised against 'anterior phonation,' maintaining that it results in a somewhat 'tight,' 'hard,' 'sharp,' 'metallic,' or 'tense' speaking voice, and is probably associated with a high laryngeal position.

2003, James Stark, Bel Canto: A History of Vocal Pedagogy, Toronto, Buffalo, N.Y.: University of Toronto Press, page 26

Sound generation in the larynx is termed phonation, and phonation types (sometimes called voice qualities) are recognisably different kinds of vocal fold vibration. All languages use a phonation type called normal or modal voice as the basis for all speech.

2005, Michael Ashby, John Maidment, Introducing Phonetic Science, Cambridge: Cambridge University Press, page 97

When the vocal folds are adducted (closed) somewhat gently, then a certain amount of air pressure from the lungs below (subglottal pressure) can set the folds into a self-sustaining oscillation. This condition is called phonation or voicing; and it involves a delicate balance of tissue coupling forces and aerodynamic forces whose overall description is still a current research topic […]

2011, Sean A. Fulop, Speech Spectrum Analysis, Berlin, Heidelberg: Springer, pages 5–6