The two-dropper mechanism in the screenshot behaves differently in different chunks. In some areas, pressing the button will pass an item from the first dropper through the empty second dropper and to the chest, silently. In other groups of chunks, items from the first dropper will stop in the second dropper and there will be a noise from an empty dropper being triggered.

When built as part of a larger mechanism, the pattern seemed to be that it worked a certain way in alternating 64-block wide bands running east-west in the world (in multiple test worlds). This more basic mechanism seems to differ across alternating east-west bands 8.5 chunks wide. For example it's silent in a chunk with Z value 0 but not in one with Z value -1.

I haven't tested every chunk, but the attached map is what the pattern seems to be. In some, but not all, chunks, rotating the setup 90 degrees causes it work/not work as well.