Fernando Zimmermann shows the physiology behind four families of vocal distortion, with scope footage of his own larynx, then the commands to produce each.

If distortion scares you or your students, this session removes the guesswork. Fernando Zimmermann opens with the research on whether rough sounds damage the voice, then takes you inside the throat with laryngoscope and stroboscope footage of his own folds plus X-ray images, showing exactly where creaky, growl, grunt and overdrive are made. Using a motor-learning framework, he hands you step-by-step commands for each: fry and lazy cartoon voices for creaky, tongue-base posture and silent throat clearing for growl, whoop posture and bursts of air for grunt, twang and extreme nasality for overdrive. He then coaches two attendees live on a high rock note and a persistent growl tickle.