I have a small scale railway soundcard that does that--the chuff stops when the whistle sounds. I'm surprised at how little I notice it. The ear fixes on the new sound, i.e. the whistle. I'm looking to put sound in my Aristo Pacific, and I'm really torn between Phoenix and small scale railways, which is cheap and simple
It seems to me on all the cards I've heard the chuff is the weak point. The Phoenix chuff sounds very processed to me. But then I have to admit I have not heard that many actual steam engines chuffing