In the process of hearing, which bone is the last of the three middle-ear bones that transmits vibration to the inner ear?

In the process of hearing, which bone is the last of the three middle-ear bones that transmits vibration to the inner ear?

• A. Malleus
• B. Incus
• C. Cochlea
• D. Stapes

Answer: (D)

Vibrations travel through the middle-ear bones in sequence: the malleus (hammer) receives the sound from the eardrum, passes it to the incus (anvil), and the incus then hands it to the stapes (stirrup). The stapes is the last bone in this chain and its footplate fits into the oval window of the inner ear, pushing on the cochlear fluids to create waves. This transfer from mechanical movement to fluid motion in the inner ear is what starts the neural signals for hearing. The cochlea is part of the inner ear, not a middle-ear bone, so it isn’t part of the chain—making the stapes the correct final relay in the middle ear.

Vibrations travel through the middle-ear bones in sequence: the malleus (hammer) receives the sound from the eardrum, passes it to the incus (anvil), and the incus then hands it to the stapes (stirrup). The stapes is the last bone in this chain and its footplate fits into the oval window of the inner ear, pushing on the cochlear fluids to create waves. This transfer from mechanical movement to fluid motion in the inner ear is what starts the neural signals for hearing. The cochlea is part of the inner ear, not a middle-ear bone, so it isn’t part of the chain—making the stapes the correct final relay in the middle ear.