Ear Mold Materials
The degree and type of hearing loss certainly plays a part in any decision regarding the selection of earmold material. As a general rule, the greater the loss, the softer the material. A mild to moderate loss can be successfully addressed with a hard, yet comfortable, acrylic earmold. Severe to profound losses, however, are best served by a snug-fitting earmold with a tight acoustic seal. A soft vinyl or very soft silicone material will provide an excellent seal and will also be quite comfortable when built for a snug fit.
While this provides some general guidelines on material selection, there are several other equally important factors that must be considered before making the final decision:
Age: When fitting an elderly patient, it is common to find very flaccid and, sometimes, sensitive skin in the ear. Similarly, pediatric patients tend to have very soft ears. In such cases, a very soft material will, more than likely, ''grab'' the skin, resulting in insertion difficulties and/or skin abrasion discomfort. An older patient may also suffer from arthritis or some other dexterity limiting condition and may find an acrylic or firmer vinyl earmold easier to insert and remove. Also, since ''younger'' patients are often predisposed to be ''tube pullers,'' a vinyl material is preferred so that the tube can be secured with tubing cement, or permanently ''welded'' to address the worst offenders.
Anatomy: The small ear canals found in most pediatric patients will not allow for adequate earmold canal structural integrity when a very soft silicone material is used. Therefore, a sturdy, yet flexible vinyl material is generally recommended for small children. Any abnormality or ''uniqueness'' found on the outside or inside of the ear will also impact the material selection process.
Other: Other factors to consider are necessary acoustic modifications (e.g. will the earmold material ''support'' a larger sound or vent bore?), the patient's experience level (is this their first earmold or are they already comfortable and happy with a certain earmold material?), cosmetic concerns and possible skin allergies.
Optimum acoustic gain will always be the primary goal. While degree of loss is probably the first step in selecting the earmold material, the challenge is to give careful consideration to each of the above factors as well, and find the balance that will achieve the goal of providing the patient with the highest degree of satisfaction.