A. If he doesn't still have a regular middle ear infection (otitis media), then he may have tinnitus. According to the Nelson Textbook of Pediatrics, tinnitus is common in children, 'especially in patients with eustachian tubemiddle-ear disease or with sensorineural hearing loss.'
Children with this condition might report a 'ringing in the ears' or hearing other noises that aren't really there.
It is possible that he had an ear infection and now just has some leftover fluid in his ear (otitis media with effusion) and that is what is causing his symptoms. Keep in mind that it is not unusual to have an effusion for up to 3 months after having an ear infection.
Does he have a lot of ear wax? Having a lot of cerumen or wax in their ears might also cause children to have tinnitus.
A Pediatric ENT specialist and/or an audiologist should be able to evaluate your child for this condition or see what else might be causing his symptoms.