Dear Parent, Ringing in the ears, also called as tinnitus can be due to various causes like listening to loud music on earphones or ear buds wax build-up,middle and inner ear infections,second-hand smoke exposure, ear injuries, certain medications like some antibiotics, chemotherapy, etc. In my opinion since your pediatrician has ruled out an ear infection, you should consult a ENT specialist who can will take a thorough medical history and do a physical exam, conduct order hearing tests to find out if there is assosiated deafness and do a blood work and imaging if required. Most of the children outgrow tinnitus, however the course of tinnitus depends on the underlying cause.