What is the cochlea?

What is the cochlea?

• A. A bone in the middle ear that amplifies sound
• B. A coiled, bony, fluid-filled tube in the inner ear; sound waves traveling through the cochlear fluid trigger nerve impulses
• C. The outer ear canal
• D. A membrane separating the middle and inner ear

Answer: (B)

The cochlea is a coiled, bony, fluid-filled tube in the inner ear. When sound enters the inner ear, it creates waves in the cochlear fluid that move the basilar membrane. This motion causes the hair cells on the organ of Corti to bend, converting the mechanical energy of the sound into electrical nerve impulses that travel along the auditory nerve to the brain. The cochlea also organizes sounds by frequency along its length, so different pitches stimulate different parts of the membrane. This is why the cochlea's role is to transform sound waves into neural signals, a function not shared by the middle-ear bones, the outer ear canal, or the membranes that separate middle and inner ear.

The cochlea is a coiled, bony, fluid-filled tube in the inner ear. When sound enters the inner ear, it creates waves in the cochlear fluid that move the basilar membrane. This motion causes the hair cells on the organ of Corti to bend, converting the mechanical energy of the sound into electrical nerve impulses that travel along the auditory nerve to the brain. The cochlea also organizes sounds by frequency along its length, so different pitches stimulate different parts of the membrane. This is why the cochlea's role is to transform sound waves into neural signals, a function not shared by the middle-ear bones, the outer ear canal, or the membranes that separate middle and inner ear.