It’s got to do with something about how pressure zones are created when you put them on. If there are fast changes in the pressure, it makes the diaphragm crinkle–or something like that. Here is the link to an article Audeze posted on their support page: https://audeze.zendesk.com/hc/en-us/articles/115001045046-Crinkling-clicking-static-sound-when-I-press-on-the-earcup
I’ve had it happen on my LCD-2’s, but it’s only when I don’t take off the headphones slowly enough. I thought it could be that, but when it’s the pressure thing it usually happens when too quickly putting on/off my planar headphones, or sometimes when I move them around. This time, it was when I began to play music, and it was only with extremely deep tones. It could have been just pressure crinkle, but I’ve never had it happen like that before. I’m still unsure what it was, and it’s only happened once.