Instrumental Visualization Techniques

Westside Voice and Swallowing


Why is instrumental visualization important?
Visualization of the vocal tract and anatomy for voice disorders provides practitioners and patients more information. This is important for determining the pathology of the perceived disordered voice quality and reviewing progression before, during, and after treatment. Videostroboscopy allows clinicians to address assessment of vocal fold vibratory patterns such as glottal configuration, amplitude of vibration, and mucosal wave characteristics which aids in interpretation of results.

What types of instrumental visualization techniques are there?
Flexible fiberoptic nasendoscopy (FFN): is performed with a flexible nasendoscope inserted through the nasal passage. The anatomy is viewed through a fiber optic bundle that transmits high-intensity light. Advantages of FFN are high resolution images of the vocal folds and velopharyngeal structures while eating/swallowing, breathing, voicing, and singing.  Disadvantages are expenses and possible patient discomfort.

Rigid fiberoptic oral endoscopy (RFOE): is performed with a rigid tube inserted into the oral or pharyngeal cavity. A prism optic system projects high-intensity light to illuminate the vocal folds and surrounding structures. Advantages of RFOE are high illumination, wide field of view, and excellent image reproduction. Disadvantages are interference with normal speech production and minor patient discomfort.


Schematic illustration: recording of the vocal fold vibration by means of High -Speed Videolaryngoscopy using (A) rigid endoscope, (B) flexible endoscope, (C) image of one vibration cycle of the vocal folds during phonation. Image credit to Pietruszewska, W., Just, M., Morawska, J. et al. (2021). 

Videostroboscopy: is performed with either FFN or RFOE, combined with a strobe light correlated to vocal fold vibration with a laryngeal microphone to view the vocal tract structures in an apparent slow motion format. Advantages are an extensive body of information relative to the effect of pathology on the process of voicing, and the potential for providing information about the neuromuscular and physiological integrity of the vocal folds and supraglottic structures. Disadvantages are patient discomfort related to the use of FFN or RFOE, and an image restricted to isolated vowel production when the strobe light is used.


Video credit: The Voice Doctor. (2011, September 21). Stroboscopy: Normal Female Vocal Cords. [Video]. YouTube. https://www.youtube.com/watch?v=9Tlpkdq8a8c

Who performs the evaluation?
Typically an otolaryngologist or speech-language pathologist performs the laryngoscopy and/or stroboscopy. If you would like to view your vocal folds, make an appointment with us! Call 212-541-4606 or email westsidevoice@gmail.com.

American Speech-Language-Hearing Association. (2004). Vocal tract visualization and imaging: technical report [Technical Report]. Available from www.asha.org/policy.

American Speech-Language-Hearing Association. (n.d.). Voice Disorders. (Practice Portal). www.asha.org/Practice-Portal/Clinical-Topics/Voice-Disorders/.

American Speech-Language-Hearing Association. Vocal Tract Visualization and Imaging. https://www.asha.org/practice-portal/clinical-topics/voice-disorders/vocal-tract-visualization-and-imaging/ 

THE VOICE FOUNDATION. (2013). Laryngoscopy/Stroboscopy. https://voicefoundation.org/health-science/voice-disorders/overview-of-diagnosis-treatment-prevention/laryngoscopystroboscopy/

Pietruszewska, W., Just, M., Morawska, J. et al. Comparative analysis of high-speed videolaryngoscopy images and sound data simultaneously acquired from rigid and flexible laryngoscope: a pilot study. Sci Rep 11, 20480 (2021). https://doi.org/10.1038/s41598-021-99948-9

The Voice Doctor. (2011, September 21). Stroboscopy: Normal Female Vocal Cords. [Video]. YouTube. https://www.youtube.com/watch?v=9Tlpkdq8a8c
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