Final answer:
The d. guinea pig is commonly used in middle and inner ear studies due to the similarity of its auditory system to that of humans. The middle ear contains the ossicles (malleus, incus, stapes) which transmit sound to the inner ear's cochlea for sound processing.
Step-by-step explanation:
The animal often used in studies of the middle and inner ear is the guinea pig. When investigating hearing, researchers tend to use guinea pigs because their auditory system is similar enough to humans for the purposes of study. The middle ear consists of three ossicles unique to mammals: the malleus (or hammer), the incus (or anvil), and the stapes (or stirrup). These bones are crucial as they transmit sound vibrations from the tympanum, or eardrum, into the inner ear where they can be processed as sound.
The cochlea within the inner ear plays a key role in hearing, as it contains receptors for the transduction of mechanical waves to produce electrical signals that the brain interprets as sound. Both the auditory and vestibular systems share structures such as the hair cells, which transform vibrations into electrical signals.