One Ding = "FA get in here now--Bring your Captain some coffee, then go serve the DL upgrades in F some free booze so they don't go whine over in the FT Skypiles Forum"
Two Dings = "FA get in here now--Otto the Autopilot needs his manual inflation apparatus operated by a FA"
Three Dings = "FA stay out of the cockpit--the front office crew is having a "don't ask-don't tell" bonding moment.
OK so I made it up.

But I
do have a selfmade "it cannot exist but a pocket video camera operated and recorded the takeoff out the window and the plane did not crash"

video whose sound track has one ding 5 seconds after rotation, the earliest I have ever recalled hearing it. Now I
am confused.