I must agree with all of the feedback stated here. The spool-up and high thrust sounds in there current state are a bit of a moodkill.
I have never been in a real A340 cockpit in flight, but in the forward cabin many times. I know Youtube videos etc. may not be a good reference, but many of these cockpit videos do bring me down memory lane. The iniBuilds does not. (Regarding the takeoff roll, at least)
In many aspects the sounds are very good. Startup and idle and in flight with lower thrust/higher speed it sounds very good actually. Exterior sounds are also quite realistic.
One thing I do have to add is the speedbrake aerodynamic sound, which is far too intense imo. I have flown in the A330 cockpit many times (which should in this sense be similar to the 340) and the speedbrake is barely, if at all audible up front. In the cabin it’s another story of course.
The topic of sounds in a desktop flightsim is a difficult one to debate. Sound engineering itself is a very technical task, but then again most feedback is based on feeling, which is a very non-scientific/non-technical thing. However, when several users get the feeling this just doesn’t sound right and even so much they take the time and effort to write feedback, it does give reason to believe there is room for improvement.