The first step in taking an ear impression is an examination of the external ear and its canal. This examination reveals several essential things:
- The size of the impression to be taken
- The length, direction and diameter of the ear canal
- The shape and contours of the external ear and canal
- The presence of any problems, such as wax, enlargement, trauma, disease, absence of the drum, etc.
Use an otoscope or video otoscope, not an earlight, to make the examination. The traditional otoscope provides illumination and magnification without visual distortion. Modern video otoscopes allow the fitter to view and record the condition of the external ear on a video screen. These devices allow the patient to see his or her own canal, and with a printer attachment, can produce copies for the file and for physician reports.
With either instrument, the hand should be braced in such a way that the fitter has absolute control over the instrument in the event that the patient's head suddenly moves during the otoscopic examination. The specula, or tips, must be sanitized (or replaced) before each use.
In adults, the canal and drum can best be observed by pulling the pinna up to straighten the canal for viewing. With pediatric patients, pull down on the lobe or pinna to open the canal for the otoscopic exam.