Symptoms of chronic otitis media include ear drainage, hearing impairment, tinnitus (cranial ringing), dizziness, ear pain, and occasionally facial paralysis. The presence and severity of these symptoms are related to whether the lesion is active; whether the mastoid bone is affected by the lesion; and whether the eardrum is perforated. Lesions affecting the eardrum or the three auditory tuberosities can cause impaired sound transmission and lead to conductive deafness. These lesions include perforation of the eardrum, destruction of the auditory tuberosities, and scar tissue formation. In acute infections of the middle ear, the eardrum can rupture and form a perforation. When the inflammation is controlled, the perforation usually heals. If the perforation does not heal, conductive deafness will develop, usually accompanied by tinnitus and fluid flow in the ear.