After my last post, I was pleased to read Trevor Marshall's comment conforting my impression about the need for meaningful sounds on a layout. But the best was when Lance Mindheim decided to add another layer of thoughts a few days later.
Interestingly, the subject seems to gather a tremendous amount of curiosity among model train operators and Ed Kapuscinski wrote to Lance about his new sound application for phone called TrainCrew. I didn't tried it yet (I'm still living in the 20th century), but from I've read and heard on his website, this is exactly what I had in mind two weeks ago while writing. The phone approach is probably the most versatile way to handle complex "sound props" while operating. No need for gimmicks or gadget. Just a good old simple device. And if you look at Ed's app, you'll see he went quite far with setting airbrake, inspection and other railroading acts that can be really bothersome to replicate otherwise.
Go check for your self!
Now, my only wish would be to have a sound replicating a hopper being emptied over a pit.
By the way, home improvement in the club layout room is nearing its end at a fast pace. If everything is going as expected, big projects like the cement plant and painting the remaining tracks in Villeneuve are about to get started. I think it's time to upgrade the plant CAD drawings!