You know, one idea I've been kicking around for over a year would be to sample about 150 random gold rings I have access to, then to sample a large random pull of round and square tabs, along with blobs of foil and other suck junk. Then burn all those sounds onto a CD, and then you could hit random shuffle while driving and play a game with yourself and try to guess what the target is going to be. 3 sounds of it first, then a slight pause, and then the voice on the CD would tell you what VDI it read and what the target was. Throw in a sheet with pics of all the ring targets so you could look and see how that ring you just heard looks, what K value, etc. I think that might be a good way to train your ear for at least what many rings *should* sound like, versus what a lot of trash *doesn't* sound like. Of course the two overlap a lot but there are general rules to rings sounding warm, smooth, soft, robust, round, and of "quality", while a lot of trash sounds harsh, bangy, sick, scratchy, tinny, hollow, and so on.