Final answer:
Fish use the lateral line system to sense vibrations and contribute to their hearing, unlike mammals that use external and internal ear structures for sound amplification and transfer.
Step-by-step explanation:
The structure that contributes to the hearing ability of a fish by sensing vibrations in the environment is known as the lateral line system. This sense organ runs the length of a fish's body and detects vibrations in the water, playing a crucial role in the fish's ability to hear.
Unlike mammals, which use the combination of external ear structures like the pinna and internal ossicles (malleus, incus, and stapes) to amplify and transfer sound to the inner ear, fish rely on the lateral line system to perceive sound and changes in water pressure.