The microphones of external portions of auditory prostheses are both highly sensitive and very fragile. As such, the microphones require protection from external elements that take the form of dirt, dust, sweat, water, and other substances that can be present in a given environment. A semi-water permeable filter can be utilized that provides a degree of resistance to substance ingress while allowing for the passage of air to a sound inlet of the microphone. However, such a solution is not able to withstand vigorous aquatic activities or other events such as significant rain, bathing, swirling dust, etc. Under such extreme circumstances, substances can be able to penetrate the -filter and can permanently degrade or destroy the microphone, rendering the device ineffective. Covering the microphone with a waterproof membrane can aid waterproofing, but the waterproof cover can increase vibrational noise.