Laryngostroboscopic Exploration of Rough Vocal Effects in Singing and their Statistical Recognizability: An Anatomical and Physiological Description and Visual Recognizability Study of Distortion, Growl, Rattle, and Grunt using laryngostroboscopic Imaging and Panel Assessment.

OBJECTIVES

To study vocal effects in singing from the pedagogical method complete vocal technique as related to specific and discrete supraglottic structures and activities by means of laryngostroboscopic imaging and panel testing.

STUDY DESIGN

This is a case-control study with a double-panel assessment.

METHODS

Twenty singers were recorded performing four of the rough vocal effects from the method Complete Vocal Technique. Two studies were performed: (1) Laryngostroboscopic examination using a videonasoendoscopic camera system and the Laryngostrobe program; (2) two blind-panel assessments with (a) voice clinicians and (b) singing teachers to investigate the recognizability of the vocal effects in supraglottic structures.

RESULTS

The four investigated vocal effects could be related to particular and discrete vibratory pattern of supraglottic structures; Distortion as vibrations of the ventricular folds, Growl as vibrations of the arytenoid cartilages against the epiglottis, Rattle as the vibration of the arytenoid cartilages against one another, and Grunt as the vibrations of the whole supraglottic structure from level 1-4 at low frequencies with a large amplitude in the vibration of the vocal folds, with particular movement of the aryepiglottic folds. The two panels recognized the vocal effects with 91%/96% accuracy for Distortion, 91%/74% accuracy for Rattle, 90%/66% accuracy for Grunt, and 83%/99% accuracy for Growl, with an overall accuracy of 91%/84%.

CONCLUSION

Vocal effects can be performed, identified, and recognized as particular vibratory patterns of supraglottic structures with no visible pathology in subjects performing the effects.