In my past experiences, periods of the quietness you described actually meant they were more active and that there had been stronger triggers. It was normally during periods of relative calm and comfort that communication was better. Not advising, but sharing, I also used THC to help facilitate communication a lot in the beginning, and I am not sure that a lot of the communication that had been, would have been without it. Which leads me to believe that without such substance abuse, it would probably be more normal for there to be less communication.

When there would be a significant trigger, protectors would take over more fully and I would get pushed back completely, so the way that I experienced that was a loss of communication, but it didn't mean they weren't there, it actually meant again that they were more active than usual, and more protective than usual.

I can also relate with the aspect of alters not really openly participating with the outside world very much, unless there is a perceived need to do so, i.e. a strong trigger. The way my system always was (and continues to be, with what is still split off), is that they had jobs to do, and they would do their jobs, but weren't very active beyond that.

For example to my knowledge they never emerged just to chat with roommates, but when a roommate became confrontational and disrespectful over something, a protector responded immediately and handled it, as I nearly blacked out completely (wound up feeling like a really weird, foggy short film).

Child alters would only come out when nobody else (other people) were around, which meant they didn't participate in socializing, either.