The necessary anatomical structures within the middle ear for the detection of sound include the tympanic membrane, the three auditory ossicles, and the two muscles that control the resonance of the ossicles. The three auditory ossicles (ie bones of the ear) are the malleus, incus, and the stapes. The tensor tympani muscle pulls on the malleus and the Stapedius muscle pulls on the stapes. The tension and relaxation of these two muscles control the amplification of sound. This acts to protect against the damage loud noises can cause to the inner ear.