Which structure is responsible for transmitting auditory signals to the brain?

The cochlea is the structure responsible for transmitting auditory signals to the brain. It is a spiral-shaped, fluid-filled organ located in the inner ear. When sound waves enter the cochlea, they cause the fluid inside to move, which in turn stimulates the hair cells located along its lining. These hair cells convert the mechanical energy of sound waves into electrical signals that are carried by the auditory nerve to the brain. This process is crucial for our ability to perceive sound, allowing us to recognize different pitches, volumes, and other auditory characteristics.

In contrast, the tympanic membrane, commonly known as the eardrum, functions as a barrier between the outer ear and the middle ear, amplifying sound waves before they enter the middle ear. The auditory canal directs sound waves toward the tympanic membrane, but it does not play a direct role in converting or transmitting signals. The eustachian tube's primary function is to equalize pressure in the middle ear and does not have a role in the auditory signal transmission pathway. Understanding these distinctions highlights the cochlea's vital role in hearing.