Disclosed herein, among other things, are methods and apparatus for providing an environmentally sealed hearing assistance device that is easy to manufacture. One aspect of the present subject matter includes a method of manufacturing a hearing assistance device. A hearing assistance device electrical component is placed into a mold and a liquid polymer resin is inserted into the mold. The polymer resin is cured into a solid state to encase the electrical component. In various embodiments, the hearing assistance device is assembled using the encased electrical component. The polymer resin is adapted to resist moisture ingress and to protect the electrical component from corrosion, shock and vibration, in various embodiments.