What have we learned about laryngeal physiology from high-speed digital videoendoscopy?
OBJECTIVE
The purpose of this review is to describe recent developments in high-speed videoendoscopy. The applications of this technique are highlighted and important findings regarding vocal fold physiology and voice pathology are discussed.


RESULTS
The number of applications for digital high-speed imaging has increased during recent years because of the development of camera image sensor systems with increased image resolution of video and television quality. Other improvements are related to computer processing speed and storage capacity and the development of automatic algorithms for quantification and measurements both in time and room dimensions. This is enhanced by combining high-speed videoendoscopy with laser-based measurement systems, acoustic analyses or other glottographic methods, such as flow glottography or electroglottography. High-speed videoendoscopy is currently used in studies of voice mechanisms of phonation (e.g., the voice source can be examined with a high sampling rate, from 1000 to over 8000 frames per second), and in phonation onset or offset. High-speed imaging is also useful in linguistic studies and in the examination of different artistic singing styles, such as extremely high-pitched singing, throat singing, or different pop and rock styles. High-speed videoendoscopy is also used in the examination of patients with voice disorders, particularly with irregular vocal fold vibrations, ventricular phonation, or the phonation of individuals who have had a laryngectomy.


CONCLUSIONS
Findings from studies of normal voice physiology and of voice disorders using high-speed imaging are presented and their relevance is discussed.
Hertegård
Stellan
S
Karolinska Institute, Department of Logopedics and Phoniatrics, Karolinska University Hospital Huddinge, SE-141 86 Stockholm, Sweden. Stellan.Hertegard@klinvet.ki.se
D004571:Electrokymography / Q000379:methods; D005931:Glottis / Q000502:physiology; D006801:Humans; D007828:Laryngoscopy / Q000379:methods*; D007830:Larynx / Q000502:physiology*; D012815:Signal Processing, Computer-Assisted; D014732:Vibration; D014743:Videotape Recording; D014827:Vocal Cords / Q000502:physiology; D014831:Voice / Q000502:physiology*; D014833:Voice Quality