Phonation

Phoneticians use the term phonation to refer to the way that sound is generated in the larynx. The important factor here is the setting of the vocal folds (a.k.a. vocal cords). Different phonation type is, for example, what distinguishes voiceless (such as [p], [f] or [t]) from voiced consonants (like [b], [v] or [d] respectively).

In addition to the most commonly occurring nil phonation (voicelessness), in which the vocal folds are drawn apart and do not vibrate, and modal (or full) voicing, when they are adjusted so that the air passing between them causes their periodic opening and closing (vibration), there are other types of phonation involving more complex configurations of the vocal folds and the space between them (the glottis).

See: breathy voice, slack voice, creaky voice