What Is The Strange Barking Noise Some Airbus Aircraft Make?

Airbus has enjoyed a successful period in the market recently, and the A320 and A330 have become extremely popular in the airline industry. But these jetliners do feature one intriguing quirk. Passengers on the A320 and A330 can expect to hear a barking noise emanating from the plane at some point during their flight! So what is the cause of this unusual barking dog sound?