From what I can tell, it seems these clocks are commercial or industrial grade, for Banks, schools, Railway/subway stations etc. The movement is actually from Germany. I'm checking to see how far off it is in time in 30 days, as I'm expecting it to be pretty accurate for a commercial clock.
As far as noise, if these were mounted in a bank or other large area, I don't think you'd notice, but since mine is mounted about 6 feet away, I hear a gentle "Whirr click flop" for one second each minute, otherwise it's absolutely silent. At the top of each hour however, when all digits flip it's a much louder "Kachunk! click! flop!" Which I hate to admit caught me off guard a few times and I jumped
The sounds it makes scared my pet parrot for a few minutes until he got used to it, but the louder noises at the top of the hour still causes him to fly off my shoulder.
I have much smaller flip clocks from the 70's that are electrically powered, they make a gentle hum and click when the digits flip, which I can sleep through. The cheap small bedside Chinese flip clock I have is noisy and tick tocks which bothers my sleep, there's a difference in how loud or quiet they might be.
For reference, here's a really nice example of Italian flip clock, I'd love to have this model so if anyone comes across it and doesn't want it, I'll take it!!
In the video when he takes it apart and puts power to it you can hear the gentle tick of each second.
http://www.youtube.com/watch?v=cbWVYXuHQJgThis video shows a large Chinese flip clock which you can find online for about $50 to $70, the audio on this video helps you to get an idea of the sounds these clocks tend to make.
http://www.youtube.com/watch?v=Vfvg2eGa6METhis commercial Bodet Flip clock has some of the characteristics of mine, large size, movement is encased, flips aren't too loud, until that thing hits 12:00 in the video, which I think mine is slightly quieter.
http://www.youtube.com/watch?v=hF6Nma1V4VQAnd this Japanese Copal flip clock sounds very much like mine, even has a neat green led flashing the seconds.
http://www.youtube.com/watch?v=7HrHyYbw_H0