To get an overview of where the various vocal effects are produced, it may be useful to describe the vocal tract’s various levels.

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 rattles’, ‘saliva rattle’ and ‘growl’ are produced.

Level 4: 
is the level of the hypopharynx and piriform fossa

Level 5: 
is the level of the soft palate, uvula, back wall of the throat 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. This is where the vowels and sound colour are produced.