The cochlear labyrinth is the portion of the inner ear that contains the cochlear duct and the perilymphatic space, which is located between the boney and membranous parts of the inner ear. The cochlear labyrinth is a fluid-filled membrane that helps in the detection of sound.

The cochlear labyrinth is primarily used to detect lower frequency sounds, such as the rumble of the bass in music. Research on primates has shown that the volume of the cochlear labyrinth has a strong inverse correlation with high-frequency hearing limits. In other words, primates with smaller cochleas have better high-frequency hearing than those with large cochleas. An example of high-frequency sound is a shrill whistle.

The cochlear labyrinth’s fluid is called endolymph. Endolymph is low in sodium and high in potassium, this mix is necessary to maintain the proper functioning of auditory (hearing) and vestibular cells, which are important for balance.

The cochlear labyrinth is one of the most sensitive structures to vertebrobasilar ischemic stroke. Vertebrobasilar ischemic stroke is when blood flow to the vertebrobasilar area, located at the back of the brain, is cut off. This area supports the brainstem, occipital lobes, and cerebellum, which means it supports functions including breathing, swallowing, vision, and coordination.

Low frequency hearing loss may result from the irreversible deterioration of the cochlea, which often occurs as people age. Studies also suggest that vertigo may be a result of transient ischemia (a temporary blockage) in the vertebrobasilar circulation.