Using OCT To Watch An Ear Hear

A team of researchers reports using an optical coherence tomography (OCT) technique to capture 3-D anatomical and vibrational images of ossicles—tiny bones within the middle ear—as they move in response to sound. OCT vibrography is an imaging method that uses optical coherence tomography (OCT) phase-synchronized with various high-frequency sound stimuli. The researchers used OCT vibrography to observe a previously unknown mode of ossicular motion at high frequencies in demonstrations with a chinchilla ear model.

The new instrument, which improves on the team’s previous design, could reveal how mechanical vibrations of ossicles contribute to sound perception in the brain. According to the researchers, it could one day be used to diagnose hearing problems.

Hearing loss can occur when the conduction of mechanical vibrations through the middle ear is disrupted by disease or damage. There are imaging methods for viewing structures within the middle ear. Still, they are susceptible to artifacts caused by nearby vibrations or necessitate surgical removal of the TM to access the structures beyond. According to the researchers, OCT vibrography could overcome both barriers by using phase-synching to image only the structures of interest (the moving ossicles) and optical coherence tomography (OCT) to image structures beyond the TM without surgical intervention. The technique could also shed light on how sounds are transmitted from the middle ear to the inner ear, which would be extremely beneficial to hearing research.

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