With my kids, I listen a lot...
As with most others, it depends on who I am with.
I tend to hike a lot with my kids (son 10, daughter 8), and I find one of the tricks to a good day is getting them started on a topic and let them roll. My daughter can hold forth on Fairy Houses in the woods for hours, and I know far more about the strategy for PlayStation games than I ever thought I would from my son.
Hiking with buddies or my wife, it's 50-50, but with long pauses most of the time.
Hiking alone, it's mostly silence until I feel the need to comment on some stupid or ill-advised thing I am about to attempt. This happens more than you might hope.