To get an overview of where the various vocal sounds are produced, it may be useful to describe the vocal tract’s various levels.
We gave the various parts in the vocal tract levels in order to identify and specify on which levels the various changes take place. The levels also make it easier to communicate where the changes take places. The levels were named as follow:
Level 1: is the vocal cord level. This is where ‘creak’, ’creaking’ ‘air added to the voice’, and ‘hammer vibrato’ are produced.
Level 2: is the level of the ventricular (false) folds. This is where ‘distortion’ is produced.
Level 3: is the level of the arytenoid cartilages/cuneiform, epiglottis and aryepiglottic folds. This is where ‘arytenoid rattle’, ‘saliva rattle’ and ‘growl’ are produced.
Level 4: is the level of the piriform fossa and posterior pharyngeal wall of the hypopharynx.
Level 5: is the level of the soft palate, uvula, back wall of the throat (oropharynx) and the back of the tongue. This is where the ‘uvula rattle’ and ‘back tongue rattle’ are produced.
Level 6: is the rest of the vocal tract (oral and nasal cavity). This is where the vowels and sound colour are produced. ‘Grunt’, ‘Scream’, ‘Vocal breaks’ and ‘Laryngeal vibrato’ are produced in a combination of various levels.