Video stroboscopy combines videotaping with a technique called stroboscopy to evaluate the function of the vocal cords, or larynx, in people with voice disorders. During speech, the vocal folds in the larynx vibrate too rapidly to permit examination with a normal light source. Stroboscopy overcomes this obstacle by using a strobe light to illuminate the larynx: The strobe emits light pulses at a rate slightly slower than the vibration frequency of the vocal folds, causing the folds to appear to move in slow motion.

An examiner may then observe the movement and function of your larynx as you make particular sounds. This is done with either a flexible viewing tube (endoscope) passed through the nose or a rigid endoscope passed through the mouth. The scope contains an optical system and a tiny camera to record the exam on videotape for later review.

Purpose of the Video Stroboscopy

  • To visualize the vocal cords
  • To identify the cause of hoarseness or voice dysfunction that may be caused by swelling of the vocal cords due to heavy use, misuse, irritations, polyps or growths or acid reflux
  • To detect or evaluate vocal cord lesions and other abnormalities such as scar tissue, inflammation or muscle tension disorders
  • To assess function of the voice box and vocal cords
  • To evaluate swallowing problems, which may be due to muscle abnormalities

Who Performs Video Stroboscopy

  • An ear, nose, and throat (ENT) specialist (otolaryngologist) or a speech pathologist

Special Concerns About Video Stroboscopy

  • None

Before the Video Stroboscopy

  • No special preparation is necessary.

What You Experience During Video Stroboscopy

  • You will be asked to sit upright, leaning a little bit forward from your hips.
  • A topical anesthetic may be sprayed on your throat and, if necessary, in your nose to make the procedure more comfortable and suppress the gag reflex. (You may still cough or gag if the endoscope touches the back of your throat or tongue.)
  • The examiner guides a flexible scope through one nostril into the throat, or holds your tongue gently with a piece of gauze and passes a rigid scope into your mouth.
  • You will be instructed to perform particular vocal tasks, such as pronouncing vowels or singing, while the examiner uses the stroboscope to visualize your vocal cords. This examination is recorded on videotape.
  • The procedure takes about 15 minutes.

Risks and Complications of Video Stroboscopy

  • The procedure has no associated risks.

After the Video Stroboscopy

  • You may resume your normal activities.

Results of Video Stroboscopy

  • After the procedure, the doctor will review the videotape with you, explain the findings, and discuss potential treatment options.


The Johns Hopkins Consumer Guide to Medical Tests

Simeon Margolis, M.D., Ph.D., Medical Editor

Updated by Remedy Health Media

Publication Review By: the Editorial Staff at

Published: 25 Jan 2012

Last Modified: 04 Dec 2014