Hey Don, I had to chuckle at hank68 and Tom-slick's answer

But when you think of it, there is really no way to ask a question of "what does something sound like", in printed text, afterall. Because sounds can only be heard. No amount of reading about how something "sounds", conveys "sound". It would be like asking "what does the note of C-minor sound like?" and thinking you can get an answer in printed text. But the only way to know, is to actually hear the note of c-minor, not read something in print.
But to add more comment to the rest of your question (as it concerns over-load signals): Yes it's true that a can-size item or larger gives the over-load signal, yet this is *only* true insofar as depth of the item is concerned. So for example: A flattened aluminum can will give an overload signal, if only 2 inches deep. However, that same flattened aluminum can at 1 ft. deep, might not give the over-load signal, since it's further from the coil. It might give a quarter TID at 1 ft. deep, for instance (albeit a different size beep, and not as clean as a surface quarter, or whatever).
Thus deeper caches might not be expected to give over-load signals, depending on their size. A refrigerator sized object will indeed give an overload signal even at 1 or 2 ft. deep, but a can may go out of the over-load range, at depths beyond 6" or so. So it all depends on the size of the object, and depth, as to whether you get the over-load signal.