Vocal effects in singing: a study of intentional distortion


Julian A. McGlashan FRCS (Otol.) 1 Mark Sayles1, Henrik Kjelin2 and Cathrine Sadolin2

Intentional Distortion is a sound commonly used in Rock and other commercial music genres for vocal effect adding a grating noise to the quality of the singing voice. There is debate as to whether this voice quality is damaging to the voice and vocal folds.

Objective: To understand the mechanism of production of Intentional Distortion during singing.

Subjects and methods: Twenty trained singing teachers in the Complete Vocal Technique pedagogic method of singing were examined using digital videolaryngostroboscopy while producing Intentional Distortion during singing. The video images were assessed by two raters and the extracted acoustic and electrolaryngographic waveforms were analysed using the Speech Studio software®. In addition one of the subjects underwent further examination using high-speed digital imaging.

Results: Sixteen subjects produced results which could be analysed. During Intentional Distortion the main contributing factor to the sound quality was the false folds (n=15). In one case the sound quality was more of creak and was produced by the vocal folds. The electrolaryngographic waveform confirmed that the fundamental frequency of vibration of the vocal folds was maintained but there is increased jitter and shimmer during the periods of distortion.

Conclusion: Intentional Distortion should be considered as an additional sound quality to that from vocal fold vibration. It is produced mainly by the false cords and can be added to a sung tone at will in appropriately trained singers for vocal effect.

This was presented by Julian McGlashan at AQL 2013, 10th International Conference on Advances in Quantitative Laryngology, Voice and Speech Research in June 2013, Cincinnati, Ohio, USA.