My light is steady blue, don’t think I’ve seen it flicker.
When mine earns, I can hear it a little bit if I just so happen to be near it, otherwise it’s completely silent.
When you earn, you’ll be selected for 1-3 epochs which lasts for 4 hours in total regardless of number of epochs. The most I’ve ever earned with my 35% node is around 11ish PRV during one 4 hour earning session.