Combining caloric testing and vHIT provides information about vestibular function across what range?

• A. Only low-frequency
• B. Only high-frequency
• C. Both low- and high-frequency canal function
• D. No relation

Answer: (C)

Caloric testing and vHIT probe different speeds of vestibular responses. The caloric test uses warm and cold stimuli to gently move endolymph, which evokes the vestibular-ocular reflex at a very low frequency—around 0.003 Hz—so it assesses how the system behaves during slow, low-frequency head movements. The vHIT, on the other hand, uses quick, passive head impulses to elicit the reflex during rapid, high-frequency head turns—roughly in the 3–7 Hz range—reflecting real-world, fast movements. By combining these tests, you get information on canal function across both ends of the frequency spectrum, from very slow to very fast head movements. That’s why the best answer is that it assesses both low- and high-frequency canal function.