It allows fluid in the cochlea to move, which in turn ensures that hair cells of the basilar membrane will be stimulated and that audition will occur.

If the round window were to be absent or rigidly fixed (as can happen in some congenital abnormalities), the stapes footplate would be pushing incompressible fluid against the unyielding walls of the cochlea.

The round window is located within the mesotympanum, at the posterior extremity of the basal turn of the cochlea.

The oval windows is also located within the mesotympanum, opening at the inferior and lateral part of the vestibule.

It has also recently been used as a site to place middle ear implantable hearing aid transducers.