Whenever I go to take video, it's a 50/50 chance there will be a clicking sound recorded with my camera. It's in a case, and I'm not sure where the noise is coming from. I don't hear it with my own ears while I'm diving, and nothing changes with my equipment over the course of the dive, so I'm not sure what's going on. For an example of the clicking, watch this -- it starts at about 0:13, and keeps turning on and off in that first minute. I assume the occasional clicking sounds might just be bigger particulate hitting the case. The case is the pt56.