||The middle ear cleft consists of a series of interconnected air-filled cavities which are located within the temporal bone. The middle ear cleft comprises:
1. the eustachian tube, through which the middle ear cleft obtains its air supply
2. the tympanic cavity (middle ear)
3. the mastoid antrum, which connects the tympanic cavity to the mastoid air cells
4. the mastoid air cell system.
The tympanic cavity is approximately 15 mm in height and length.
It resembles a flattened box set on edge, with a pipe emerging from its narrow front wall-the eustachian tube .