Ear Impressions

Making a Perfect Ear Impression

The ear impression is perhaps the most important step in the hearing protection process. It must accurately depict the outer ear in order that the most comfortable and correct fitting can occur.  It is important to work with someone who understands the correct way to make the impression, and who uses the correct materials. The process of making impressions is simple, fast and easy. Basically, I will place a small piece of cotton into the ear canal to stop the material from going where it shouldn’t, then I mix a two-part putty-like impression material, inject the material into the ear canal using a plastic tipped syringe, wait a few minutes, then I will slowly remove the impressions.  Below are the steps I take for making amazing impressions.

Step 1: Examining the Ear

The first step in taking an ear impression is an examination of the outer ear and the ear canal.  During this step I will be looking for several essential things:

• The overall 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, and the presence of any problems, such as wax, enlargement, trauma, or disease.

Step 2: Insert the Cotton Stop

I will gently work the cotton block into the ear canal, checking to make sure it properly fits into the ear canal.

Step 3: Mix the Material

With the cotton block correctly and accurately placed in the ear, I will prepare a two-part, high-grade impression material.  I will use one part high-grade silicone base and one part high-grade silicone hardener.  Then I will knead the two materials together, working quickly, until the silicon is a uniform color.

Step 4: Open Mouth and Insert the Bite Block

Typically we will be making open-mouth impressions, that require a bite Block between your front teeth, allowing your jaw to still throughout the remainder of the procedure. The effect of using a bite block to make open-mouth impressions is to slightly enlarge the ear canal, which produces slightly larger ear impressions, and therefore slightly larger finished ear plugs or ear molds. Since the finished earplugs or molds will be larger, they will fit more snugly in the ear and the seal they make in the canal will be more likely to remain intact even when the mouth is opened, as in singing or talking.

Step 5: Put Mixed Material Into the Syringe

After the bite block is in the place and the jaw stabilized I will place the kneaded impression material into a plastic syringe and, using the plunger, push the material down into the tip until it is within 1/8” or so of the end. This will remove the air pockets from the material.

Step 6: Fill the Ear Canal and the Outer Ear

I will then place the tip of the syringe into the ear canal, and squirt the material into the ear filling the ear canal, slowly withdraw the syringe and continue filling the helix, bowl, and tragus areas of the outer ear.

Step 7: Let the Impressions Cure

Now we will need to let the silicone impression material cure by waiting 5 minutes for the material to set up. When ready, the material will be firm to the touch with no give at all when I press on the material. I will allow ample time for the impression to cure will ensuring that your impressions will retain their correct shape after removal from the ear.

Step 8: Carefully Remove the Impressions

When I am sure the impressions are fully cured, I remove each impression by working my fingers under the edges of the impression the I will gently remove the impression from the ear.

Step 9: Inspect the Impressions

After the impression is removed from the ear I will carefully evaluate the impression for accuracy.  Fortunately, I have spent my career making accurate impressions, and I typically get a perfect impression each time.  However, every once in a while a part of the impression will not be up to my high standard and I will remake the impression.