Abstract: A method of processing an impression of a portion of a user's ear canal that produces a flexible hearing aid housing which duplicates the shape of at least a portion of that impression. A female mold is created using the previously obtained ear impression. A compliant molding material is used to form the female mold. The same material is used to form a male mold in the cavity left in the female mold when the ear impression has been removed. Subsequent to curing of the male mold, it is removed from the female mold and covered with a curable, hardenable plastic such as a UV curable acrylic. Once cured, the compliant male mold is removed leaving a rigid plastic shell whose internal volume conforms in shape to the exterior shape of the ear impression. Mandrels can be inserted into the volume to provide post molding compartments for electronic components. A matrix can be inserted into the internal region or wrapped around the mandrels or respective components.