Voice quality types and uses in North American English.

Voice quality has been defined variously in the literature ranging from states or postures of the glottis and vocal tract in general most broadly, to a narrower definition which refers to characteristics of vocal fold vibration during . Linguists have traditionally broken the continuum into five basic categories based on roles they play in a language's phonology: , , . Of these, the three central states, , , are relevant to voice quality as discussed in this work.