My Flute is rattling

[Walrus]

When I play in the middle register w the RH keys, my Flute begins making this awful buzzing/rattling noise, like there's a mosquito in my ear. I thought it was just a problem with my open-hole Flute so I took it to the shop to have it looked at (and of course the rattling stopped), but my closed-hole Flute makes the same noise when I play the same keys!
I haven't changed anything about my mouth or hands or the amount of time I play, but I never noticed this noise on either Flute until recently.
Have any of you ever experienced this before? Any ideas on how to fix it?

[pied_piper]

Be sure the crown on the end of the headjoint is snug, but don't over tighten it, just snug only. Other possibilities include a loose screw, a loose spring, a torn pad skin, or something else. There are a lot of possible causes.

[fluteguy18]

Indeed! I once looked for about 2 hours before I found the cause of a mystery buzz. The culprit? A spud that was coming unsoldered.