Ear infections commonly result in mild hearing loss and generally get better after the infection has cleared, however, infections and build-up of fluid in the middle ear that occur can result in more significant hearing loss. Infants or toddlers may experience delays in speech and social and developmental skills. Infections in the ear that don’t respond well to treatment, or untreated infections can spread to nearby tissues. Mastoiditis is an infection of the boney structure behind the ear that can lead to cysts or damage to the bone. Though rare, serious middle-ear infections that spread to the skull, including brain membrane, can cause meningitis.