Fiber-optic instrumentation is most appropriate for evaluating which aspect of voice production?

• A. Articulation
• B. Phonation
• C. Proprioception
• D. Respiration

Answer: (B)

Phonation is what fiber-optic instrumentation is best for evaluating. A flexible endoscope lets you directly visualize the larynx and vocal folds while someone is producing sound, so you can see how the folds come together (closure) and how they vibrate during phonation. With strobe or high-speed imaging, you can assess the vibratory pattern, symmetry, periodicity, and the presence of any irregularities or lesions affecting voice quality.

This tool isn’t designed to assess articulation, which depends on the tongue, lips, and jaw shaping sounds. It also isn’t the right method for proprioception, which is about the sense of body position, or for respiration, which is about airflow and lung function and is typically evaluated with spirometry or airflow measures. So the focus of fiber-optic instrumentation is the voice’s phonatory function.