Final answer:
The medical assistant should use written communication or gestures to convey information to a hearing-impaired patient.
Step-by-step explanation:
When checking in a hearing-impaired patient, the medical assistant should use written communication or gestures to convey information. This ensures effective communication with the patient. Speaking loudly may not be effective if the patient cannot hear well, and assuming the patient can lip-read may lead to misunderstandings. Requesting a family member to interpret is not the best option as it may violate patient privacy and the family member may not be qualified to accurately interpret the information.