The hearing aid fitter must evaluate each patient prior to material and style selection, and must address each of these considerations:
Who is your patient -- an active child or a sedentary, perhaps senile, senior?
What can the patient handle? What are the limitations?
What material and/or styles can improve --or adversely affect -- ease of insertion?
Hearing aid gain
What degree of seal is necessary to contain the hearing aid's output?
What are the amplification objectives of the fitting?
Are there any known allergies to plastics?
What is the appropriate color for the earmold and/or tubing?
What limits are imposed by the patient with regard to acceptability?
Do you anticipate an easy fitting and adjustment period, or do you need to allow for potentially numerous earmold modifications after the delivery?