 This is a really great example of all the potential things that can go wrong, unfortunately, with hearing in a child with Down syndrome. So this patient had both conductive as well as sensory neural hearing loss. So we would start with the outer ear, and what we noticed with the outer ear is that there is cartilaginous stenosis of the external auteuric canal. We have somewhat of an unusual appearance of the helix of the ear. So this is an example of external auteuric canal stenosis. It's not atretic, but it's stenotic. As we come to the tympanic membrane, which of course is the border of the external ear laterally from the middle ear, medially, we have a myrhingotomy tube, so a tube that has been placed because the patient has had problems with chronic otitis media. The bony external auteuric canal, which is this portion here, looks normal in its caliber. We next look at the ossicles, and the ossicles look pretty good. There's the malius and the incus and the neck of the malius and the long process of the incus, and we have our stapes, foot plate, and the incodostipedial joint. So that all looks fine, and so we can pass the middle ear potentially. However, when we get to the inner ear structure, we first look at the vestibular aqueduct, which is normal in its caliber. Then we start looking at the vestibule and the cochlea. This is an example of very tight cochlear aperture stenosis. As we come from the internal auteuric canal, and we come to the cochlea, we can barely see the opening from the internal auteuric canal to the cochlea. This is cochlear aperture stenosis. The measurement of this has been done by multiple different groups, and most people would say that 1.5 millimeters or less represents cochlear aperture stenosis. Now that's right at the aperture. The other thing that I've demonstrated previously is you can have a bony block in the middle of a relatively normal caliber to the aperture, and we would still call it a bony aperture stenosis. In this case, really tight, narrow aperture. I glossed over this, but as I was talking about the internal auteuric canal, hopefully some of you would have looked at this and said, this is not a normal width of an internal auteuric canal. It is narrowed. When we have narrowing of the internal auteuric canal, we're obviously going to be concerned about the potential for cochlear nerve hypoplasia. We would have to do the MRI scan to look for the cochlear nerve hypoplasia, but a narrowed internal auteuric canal with a cochlear aperture stenosis is going to put the patient at high risk of not having a normal cochlear nerve. Finally, and this is unusual, we note that there is a small halo of low density around this cochlea. What I'm referring to is this low density of bone, which is not part of the cochlear itself, nor its medialis. This is additional abnormality. In this case, this patient is unfortunate enough to also have the cochlear form of otospongiosis. This patient also has otosclerosis seen as this little halo of demineralization around the cochlea. This low density around the cochlea, even here, should not be there. This is abnormal low density and is an example of the retrofenestral or cochlear form of otosclerosis or otospongiosis. Let's just look at the contralateral side and look for any abnormalities there. It too has this low density around the cochlea, identifying the otospongiosis. Once again, we have cochlear aperture stenosis and a narrowed internal auditory canal. This is the singular canal coming to the vestibule here. This patient who has Down syndrome in this example has a normal bone island and a normal peering vestibule and lateral semi-circular canal. Here you have another example of external auditory canal stenosis with middle ear cavity inflammation. The patient actually has some mastoid inflammation here. Here's the mirroring Godamie tube going through the tympanic membrane to help drain the middle ear cavity. An unfortunate patient who has Down syndrome who has both congenital abnormalities in the external ear as well as in the inner ear, but superimposed, an inflammatory process known as otospongiosis which we will discuss shortly.