Final answer:
The air cavity above the mastoid air cells is part of the middle ear, which contains the ear ossicles and is associated with the petrous part of the temporal bone.
Step-by-step explanation:
The air cavity in the temporal bone above the mastoid air cells is part of the middle ear space which is housed within the temporal bone, between the ear canal and bony labyrinth.
The middle ear contains the ear ossicles that amplify sound waves from the tympanic membrane to the oval window, aiding in hearing. These structures are located in the petrous part of the temporal bone, which also contains important nerve passages such as the internal acoustic meatus for the nerves associated with hearing and equilibrium.