I find it interesting that you feel that way regarding the sound, yet the very model and the layout it runs on are not, and can never be, so literally like the real thing. Gravity and mass doesn't scale; there's no exhaust; the layout around the model will be full of people who don't move; water doesn't flow; clouds don't move and change their shape; there will be gaps in the sky where the room the layout is in show through; etc., etc.
I think sound is like all the other modelling we do: we want it as close as is reasonably possible to the real thing, but we must by definition accept it isn't the real thing.
Kudos for Accurascale though, on putting the effort in to get these Deltics as close as possible to the real thing. I await mine eagerly (likely to be at the a*se end of the deliveries...)