Question

If the stapes became fused to the other middle ear bones or to the oval window, how would this condition affect hearing? Explain.

Short answer

The function of the stapes is to facilitate sound transmission towards the oval window of the basilar membrane. If this structure fuses with the other bones of the middle ear, it will lose its functionality, and the individual will suffer from hearing loss.

Step-by-step solution

Structure of the ear

The sensory organ of hearing, that is, the ear, has several components grouped into three parts: the outer ear, the inner ear, and the middle ear. Each of these parts has a different set of structures that sequentially transmit the sound signal towards the brain.

The middle ear

The middle refers to the part of the ear lying between the pinna (outer ear) and the inner ear. It comprises the eustachian tube along with three small bony structures (a characteristic feature of mammals). These bony structures are the stapes, malleus, and incus.

Result of fusion of stapes and other middle ear bones

The stapes and the other two bones of the middle ear are separate structures and function to transmit the incoming signals of sound to the oval window, which further transmits the signal to the brain for interpretation.

If the stapes gets fused with any of the incus and the malleus bones of the middle ear, it will not be able to function properly, and the transmission of the sound signal will stop. This, in turn, would result in loss of hearing.