According to QANTAS on their website...
"On our Airbus aircraft you’ll hear the ‘boing’ sound shortly after take-off – this sound lets crew know that the landing gear is being retracted. (Depending on where you are sitting, you can probably hear or feel it moving. If you’re downstairs in the pointy end of one of our Boeing 747’s – you’re basically sitting right on top of the front landing gear)."
Do the cabin crew really need to know this. How does QANTAS inform the cabin crew on Boeings when the gear is retracting?
https://www.qantasnewsroom.com.au/ro...rew-lingo-101/