AudioParameterInt etc

[daniel]

Unfortunately the AudioProcessorListener is misleading. Eventually it was meant for that purpose, but here is explained where the audioProcessorListener is actually used:

AudioProcessorListener is not notified when host changes parameter

That's because each wrapper (which is the gate between the Host and the AudioProcessor) is an AudioProcessorListener, therefore when an object that is an AudioProcessorListener calls setValue() it doesn't exactly want a callback to tell it the value has been set. Think of "setValueNotifyingHost" as actually being "setValueNotifyingListener". I think to be honest you probablt shouldn't be using theAudioProcessorListener unless you are creating a new wrapper.

That explains, why you are not notified, when the change is a result from the host.

If you want to have callbacks from the AudioProcessorParameters, I found AudioProcessorValueTreeState with AudioProcessorValueTreeState::Listener::parameterChanged() very handy.
There is also a AudioProcessorValueTreeState tutorial, and some months ago I played around with it on github - tapeDelay