Phonak Lumity, Phonak Paradise & Phonak Marvel Ceru Shield changes. Often the wax filter plug now called a Ceru Shield Disc gets blocked with wax and debris compromising the performance of the hearing aid. People unsuspectingly think their hearing aid is broken when it often is simply a blocked wax filter. This video shows you how to change your wax filters or Ceru Shields that hide beneath the rubber domes. Easily over looked or forgotten about I am routinely reinstructing my clients to change their wax filter system when it appears their hearing aids have stopped working. Hence this coaching and instructional video.