What separates the middle ear from the inner ear?

The tympanic membrane, commonly known as the eardrum, serves as the critical boundary that separates the middle ear from the inner ear. It functions to convert sound waves into vibrations, which then travel to the ossicles—small bones in the middle ear that amplify the sound. This structural separation is vital for the proper transmission of sound from the external environment through the ear canal and into the inner ear, where sound is processed and converted into signals for the brain.

The other components mentioned play distinct roles in ear function but do not serve as the boundary between these two sections. The cochlea is part of the inner ear, responsible for converting sound vibrations into neural signals. The eustachian tube connects the middle ear to the throat and helps equalize pressure but does not separate the ear sections. The ossicles, consisting of the malleus, incus, and stapes, are located within the middle ear and are crucial for the conduction of sound but do not divide the middle ear from the inner ear.