These are the Rebbe's letters to individuals about their own situations. Throughout, the Rebbe instructed people to consult an expert doctor and follow his guidance; anyone facing a medical question should do the same.
The Rebbe's guidance on ear problems:
Consult an expert doctor (IK 4678). Ear discomfort of the kind described can come from eczema in the ear; there are doctors who treat this with an ointment and by keeping water out of the ear. The final decision rests with the treating doctor (IK 8272).
Ear surgery done by a specialist in the field, such as the procedure involving the small bone of the ear, is a minor procedure, and it is proper to go ahead (IK 5829).
Immersing in the mikveh with an ear condition: place a cotton plug soaked in water in the ear. In many cases doctors permit this from the outset (IK 8910, 4678).