Can Grommet Insertion In Both Ears Cause Permanent Damage To Ears?

Hi.My son has persistent pain in his right ear.He had grommets inserted in both ears about seven months ago.A few weeks ago he had a cold which left him feverish and with acute ear pain.I took him to an audiologist who said that his ear was `blocked` by ear wax and thus advised olive oil drops to be used in order to clear the wax before he can know what to do with the ear.Some wax has been coming out along with some crusty dry opaque - coloured stuff.The hearing in his right ear has been ruled out as below par.Does this mean the grommet is blocked or has it become dislodged? Will this cause permanent damage to his ear? He is in pain and complain of discomfort and ringing in his ear.Please help.