Inner Ear: It is one of the three main regions of the vertebrate ear that contains the cochlea and the semicircular canals. The cochlea thats located in the inner ear propagates these mechanical signals as waves in fluid and membranes, and finally transduces them to nerve impulses which are transmitted to the brain. The vestibular system of the inner ear is used for the sensations of balance in motion. Sends what it hears to the brain.