This is a strange one. Sounds like something moving inside the headphone (QuietComfort 35 II)

I'm not sure where to post this and I was wondering if anyone might have had a similar experience or can explain what I'm hearing.

I use my headphones (QuietComfort 35 II) for sometimes 8 hours a day+. I have a lot of problems with sensory overload and these babies which I bought in June of 2020 have been lifesavers. I've had to replace the earpads a number of times but it's been easy since they're designed to be replaceable (and another reason for my love-affair with bose). Lately, in the last few months, I've noticed something very odd; the sound of something moving in my right ear. I'm pretty sensitive to sounds so I can tell when it's a sound from in my ear or something rubbing on the outside, but this is different, it really sounds like it's from inside the headphone itself. I thought it may be a loose component so I try to rattle my headphones a bit to see if that affects anything but the noise happens independent from any movement. Sometimes it happens when I'm doing chores, sometimes it happens when I'm laying in bed. It's SUPER disconcerting to tell the truth. It sounds like I imagine a bug squirming in your ear would sound. Very creepy.

I don't actually think there is a bug in there (I keep a tight and tidy ship with my headphones) but I would be interested to know if this is a common occurrence with wear-and-tear or a sign I should start putting away money for replacements.