<prompt> Which of the following is NOT a content of medial wall of middle ear:Oval windowRound windowProcessus cochleariformisAditus ad antrum  <response>: Ans. d Aditus ad antrumReft Dhingras ENT 6th edj 5-6 Aditus ad antrum is located on posterior wall. It is a doorway to antrum of mastoid. Antrum is largest mastoid air cell. 