They don't ring. They're much too small.

The only minor danger I was afraid of was being unable to go through MRI machines with those of my implants that have a ferrite core - i .e. small glass implants. But it turns out, they're completely unaffected - at least up to 2T, which was the strongest MRI field I went through. They do warp the MRI scan pretty badly around them though 🙂