This is only something I’ve noticed today, and its bugging me!
I recently aquired a Fender tele, though I may well have the problem on my other guitars too..
I was playing a little repeating type solo, the intro part to the first Master of Puppets solo, so had a lot of gain on the amp too. Its basically a bunch of notes on the high E and B strings.
So while I’m picking that my palm is resting on the rest of the strings around the bridge area to keep them muted.
But as I’m picking, my palm moves, because obviously my wrist moves with my picking actions. This movement, while keeping the unwanted strings from ringing out, makes a whooshing/scraping kind of noise.
Like if you rest your hand gently on open strings but not hard enough to fret any and slide it up and down, that kind of effect.
Basically string squeak.
As I’m picking and the movement being short and staccato like, it sounds like a chopper. Once heard was very hard to un-hear!
I’ve noticed I hear my pick attack through the amp when using other guitars, but not excess ‘string squeak’ from the picking hand!
The only easy day, was yesterday...