I have hydraulic ones on my new coach. I don't know if they beep, but I have seen the center lamp blink along with one or more of the arrow lamps. In my case, it was telling me that the jacks were fully extended and the coach was not level. I put blocks under the low point (twice) before it was able to level the coach.
2010 Winnebago Tour 42AD, Cummins ISL 400, Allison 3000, Progressive EMS, Aventa II, Air Force One, Tire Safeguard TPMS, Blue Ox Tru Center (maybe), Lotsa LEDs