Nerve and conduction deafness can both occur as a result of acquired hypothyroidism, as can vertigo and tinnitus. Symptoms usually resolve with thyroid hormone replacement. It's thought that serous otitis media, edema and swelling of the nerves may contribute to hearing loss in hypothyroidism. Deafness is also associated with Pendred's syndrome of congenital hypothyroidism and with thyroid hormone resistance. In these cases, however, hormone replacement doesn't improve the sensorineural hearing deficits. HL