You know I've been putting Ivory ferrules on my personal Qs, plus many others for 20 plus years. I keep hearing this thing about the "ping", "tink" & other noises from Ivory ferrules. I think the "noise" that people hear, is from badly installed ferrules. I'm presently playing with 3 Qs that have Ivory ferrules. They do not have a funny noise emminating from the ferrule. I beleive that the "noise" comes from installers, who use a pointed drill bit to drill the pilot hole in the ferrule. That makes a hollow sound from the void in the tip of the ferrule. If you use a flat faced drill or shape the tenon to fit the shape of the drill tip, you will get a solid & firm hit from Ivory ferrules...JER