Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice. The most common damage of the ear when a foreign body perforates it, is eardrum rupture. Adults having ear trauma, may complain hearing loss, ear pain, spinning sensation, ringing in ear, nausea or vomits, but in three years old child it s difficult to define if there is eardrum damage only from symptoms. You should take him to the pediatrician for an ear examination to check if there is any eardrum perforation. Usually in children, perforated eardrums heal without treatment within a few weeks, but sometimes it requires some other procedures to close the perforation. Hope I have answered your query. Let me know if I can assist you further.