11. The tympanic bulla, which encapsulates the middle ear , is also large. 12. Fluid build up following middle ear infections may cause this. 13. At the same time, diagnoses of middle ear infections and sinus infections are increasing. 14. Otitis media ( infection of the middle ear ) can threaten a child's hearing. 15. The stapes is the third bone of the three ossicles in the middle ear . 16. Also uniquely amongst tetrapods, the scolecomorphids lack a stapes bone in the middle ear . 17. Chronic infection of the middle ear can cause hearing impairment. 18. The mastoid air cell system is a major contributor to middle ear inflammatory diseases. 19. Admittance is how energy is transmitted through the middle ear . 20. These processes form notches that may be tympanic fossae, cavities of the middle ear .
