(WYTV)- We’ve all heard them when we’re flown but no doubt paid little attention to them: those little pings, almost like chimes that echo through the cabin.

Two in a row, maybe three in a row, maybe only one. What do they mean? They’re signals and they do mean something.

The dings and pings will typically let you know when you should stay seated and when you can move around the cabin.

But airline pilots and crews also use the sounds to communicate with each other. Each airline has its own internal code, a kind of morse code at 30,000 ft.

They can mean the seatbelt light is now on or off, a certain passenger needs help with something, it’s going to get bumpy, we need more refreshments or we’ve just reached a certain altitude.

The crew knows all about them and they differ from airline to airline.

For example, on Qantas Airways out of Australia, a high-low “ding-dong” means the staff wants to get each other’s attention but it’s usually a non emergency.

  • A triple low chime warns the flight attendants turbulence ahead, lock down your snack carts.
  • Two airplane chimes on a U.S. Airways flight signal that the plane is approaching 10,000 feet.
  • Three or more chimes mean we have a sick passenger who needs medical attention.
  • And one chime can warn flight attendants of bumpy skies.

The airlines really won’t tell you. It’s one of the mysteries of flying.