Sounds like they are starting to relax and settling in. Youngsters are normally chatting away the whole time, so to hear them is a very good sign! Wthey will come out once they are ready to take on the wider world.
Just try to tempt them with talking to them gently the whole time and get them to pick up treats. It helps create a little feeding rituals, like rattling a plastic bag or like me, making a tsk tsk sound - they usually pick up on that within days and will soon start to wheek for food!