Out of curiosity, what causes that strange arrow vibration noise in flight?  I used to hear it from my aluminums off my compound (finger release) back in the 90s.  I still hear it on occasion (1/4 shots) on my carbons.  I don't think I ever hear it on woods.  It's hard to describe a sound in words but it's a sort of buzzing sound, very different from the noise soft feathers make in flight.  Is my arrow hitting something just as it's leaving the riser?  Or is this my screw-in heads losening & rattling on the way to the target?

Feathers can make a lot of different sounds.  If you're sure it's not them, very loose points can also make noise.  If you were banging your arrows off the shelf, you would hear one loud crack. Are you certain you're not hearing string noise?

Loose points.

I'd guess points loose. I put a dab of string wax on my threads. Never have to worry about loose points again.  If you think it might be the feathers try a bare shaft and see if you still hear it. That's what I've done in the past.

The wax on the thread tends to work loose for me.
I take and use two or three wraps of dental floss on the threads before screwing them into the inserts.

Aluminum are hollow and can 'ring'.  Wood and carbons don't do that.