The eardrum, known medically as the tympanic membrane, is located at the base of the external auditory canal and is the boundary between the external auditory canal and the middle ear. It is similar to a round or oval shape, about 8mm x 9mm in size, and is very thin, mostly a translucent membrane, not more than 0.1mm thick, and its entire surface is not completely flat, but is conical in shape, with the bottom of the cone attached to the lowermost end of the hammertone of the hammertone bone, which is known as the umbilicus of the tympanic membrane. The tympanic membrane also has a reflective point, in the light of the light can appear cone-shaped reflection, called the light cone of the tympanic membrane. If the cone of light disappears, the shape of the eardrum has changed. This may be due to the presence of certain pathologies, such as inflammation or a change in middle ear pressure or fluid buildup in the middle ear, which can cause a change in the shape of the eardrum.