Can you hear your muscles?

I’m pretty sure that most of us have heard blood travelling through our own ears whilst laying in bed late at night. Last night I was lying with my head sideways on my open hand when I noticed that if I moved my thumb even minutely, not even enough to move it, I could hear something. It was a rapid low pitched ‘clicking’ and I got something similar from my jaw muscles  forearms too. Am I hearing my own muscles

Is it just me that gets this and am I a freak? Am I hearing my own muscles?

I have tendonitis in my knee. I hear this crunching noise every time I walk up the stairs.

No but I can see them.  They twitch. Calf muscles particularly will twitch, undulate and move freakishly while I’m just sat still. Like there are insects running around under my skin.  24/7 – it never stops. I forget about it for ages and am then shocked anew when I notice it again!

Yep, it sounds a little like an air bed being blown up.

I think you are hearing the tendons running within their sheaths rather than muscles themselves. My knees creak occasionally (have done since my early 20s) but I don’t think I’ve ever heard a muscle.

Nope; not tendons, at least I really don’t think so. If I keep the ever so slight tension static so that the tendons are not moving but are under strain I can still hear the noise. It is continuous until I stop tensing. ‘Tensing’ seems to be a far too strong word here, all I am doing is to just barely activate my muscles.