1.2.0 Engine Start Sound incorrect?

[Airbusfahrer]

Hey there,

ever since owning this aircraft (which is fantastic and good fun by the way) I asked myself if the engine start sound is really correct. The Trent XWB has this very distinctive growl when starting, very similar to the GE90. In my head, this should start exactly when the fuel flow starts and the combustion starts. In my sim, this sound starts much later, like five to ten seconds after the fuel flow starts and EGT rises. You can observe this behavior in many streams online as well.

I started some research and looked for videos showing the startup. Unfortunately, there are not many showing the ECAM on startup. However, there is one I found, which is this one: 

Notice at 0:33, right when the fuel flow starts and EGT rises, the growl in the background is audible.

So, question to you: Is the sound of the aircraft in the sim actually correct?