Most modern otoscopes use a single-use, disposable speculum (the pointed part that you put into the person's ear). Specula come in different sizes, and the proper size should fit snugly into the outer third (no more than 2 cm (0.79 in) deep) of the person's ear canal.  Use the following guidelines for speculum size: adults, 4-6 millimeters; children, 3-4 millimeters; infants, 2 millimeters. The speculum usually just snaps onto the pointed part of the otoscope. Dispose of the speculum after a single use. If you have a reusable speculum, sanitize it thoroughly according to the product instructions. Flip the switch or push the button to light up the tip of the otoscope, then grasp the handle between your thumb and forefinger like a pencil or pen. Touch the back of your holding hand to the person's cheek to help steady both your hand and the scope.  Be calm and move gently during an examination of someone else's ear. Many people don't like the feeling of having something stuck into their ear, and the ear is a very sensitive organ that can be easily damaged. If possible, watch a medical professional use an otoscope before trying it yourself. Lightly pinch their outer ear between your fingers, at either the 10 o'clock (for the right ear) or 2 o'clock (for the left ear) positions. Gently tug their outer ear up and back—this will straighten out the person's ear canal and make it easier for you to get a clear view inside. If you're checking a child under 3 years old, try gently pulling the outer ear downward first. This may provide a better view. While keeping the back of your holding hand against the person's cheek, carefully place the tip of the speculum into the outer section of their ear canal. Look into the otoscope with your dominant eye and close your other eye.  Do not press the speculum into their ear canal with any amount of force. Simply guide the tip 1–2 cm (0.39–0.79 in) in. If it won't go in easily, you likely have too large of a speculum attached. If the person indicates any pain or discomfort, stop immediately and carefully withdraw the otoscope. Have a medical professional do the examination instead. Begin your examination at this angle, which follows the path of the ear canal. Once you have a clear view, gently move the otoscope around at different angles to examine other parts of the eardrum and ear canal walls. Quickly but carefully withdraw the otoscope if the person says they feel pain or discomfort. You aren't a trained medical professional, so don't try to diagnose any type of ear problems. If the person is having ear troubles of any type, tell them to see a doctor. If they aren't having any problems, though, look for the following signs to confirm a healthy inner ear:  The ear canal itself should be flesh-colored and covered in tiny hairs. It's also normal to have some brown or reddish-brown earwax on the canal walls, but the wax shouldn't be blocking the canal. There shouldn't be any signs of swelling. The eardrum should be translucent and white or gray in color. You should be able to see tiny bones pressing against the inside surface of the eardrum. Draw the speculum straight out of the person's ear canal and pull the back of your hand off of their cheek. Let go of their outer ear with your other hand. Now you can check the other ear. Checking someone else's ears, or having them check yours, is never an adequate substitute for a proper medical checkup. Use an otoscope only to confirm that your inner ear looks healthy, not to diagnose a problem when it doesn't feel right.
Attach an appropriately-sized speculum to the otoscope. Turn on the otoscope's light and hold it like a pencil. Straighten the person's ear canal with your free hand. Insert the otoscope's speculum 1–2 cm (0.39–0.79 in) into the ear canal. Point the tip of the otoscope toward the person's nose first. Look for common signs of a healthy ear. Remove the otoscope carefully and slowly.