What structure separates the outer ear from the middle ear?

The tympanic membrane, commonly known as the eardrum, is the structure that separates the outer ear from the middle ear. This thin, cone-shaped membrane vibrates in response to sound waves, and these vibrations are then transmitted to the ossicles (tiny bones) in the middle ear. The tympanic membrane plays a crucial role in the auditory system, as it converts sound energy from the air into mechanical energy that can be transferred to the inner ear.

The auditory canal, while part of the outer ear, is a passage that leads to the tympanic membrane but does not serve as a barrier between the outer and middle ear. The pinna is the visible part of the outer ear that helps collect sound waves but does not separate the ear sections. The cochlea is part of the inner ear and is responsible for converting vibrations into nerve impulses that are sent to the brain, making it unrelated to the separation of the outer and middle ear.