The Mégane II Owners' Club

I recently left the interior light on & flattened the battery on my '53 1.6 Megane & so lost the radio code.
However, I've now noticed (without the noise of the radio!) that if the throttle is blipped or "stabbed" from idle, there's a momentary burst of a hissing sound coming from the top / rear vicinity of the engine (throttle body/manifold area) just before the engine revs pick up. I wondered if perhaps an air leak had developed, but the car seems to drive ok (no warning lights etc).
It's a strange sound I've never heard before coming from any car!
Has anyone any idea if this is normal on this engine

That sound is normal I think, mine does it too...

So does mine, a 2.0. Just induction noise, I guess.

Thanks for that; I guess I'm getting a bit paranoid in my old age!

could be airbox loose mine did the same looked under bonnet and saw that the airbox had come undone from throttle body