Final answer:
Cochlear implants can enhance hearing abilities but do not improve vision and mobility, memory retention, or reduce the risk of stroke.
Step-by-step explanation:
A cochlear implant is a device that can restore hearing in people with a nonfunctional cochlea. It consists of a microphone, a speech processor, a transmitter, and an auditory nerve. By picking up sound, selecting sounds in the range of human speech, converting them to electrical impulses, and sending them to the auditory nerve, cochlear implants can enhance hearing abilities. However, they do not improve vision and mobility, memory retention, or reduce the risk of stroke.