Your health care provider may diagnose an ear infection by examining the ears and using an instrument called an otoscope, looking for a red, painful outer ear, redness or swelling of the eardrum, fluid, or perforation in the eardrum. As part of the exam, your health care provider may also examine the throat, sinuses, head, neck, and lungs.
Sometimes, additional tests for ear infection are recommended, especially if your child has had fluid in the middle ear for some time or has had chronic or recurrent ear infections:
Tympanometry - This test measures eardrum movement. A soft plug is inserted into the opening of the ear. The plug includes a device that changes air pressure inside the ear.
Acoustic reflectometry - During this test, the health care provider uses a hand-held instrument to project sounds of varying frequencies into the ear. How the sounds are reflected indicates differences between empty space and fluid.