I used to have 2 chicks brooding in my house. I KNOW what your talking about... lol, and for those who are used to large groups, the peeps from just two are worse... Lol, something about not having the constant peeps, but more like sporadic and yet at the same time constant din.
If you can sleep with it... Try turning on a radio music station on a very low volume. Your not really trying to drown out the chicks, but give them AND you something to listen too. I also found that adding a mirror near where they sleep helped out on the noise level, almost like they felt like there was 4 of them and not just two. Lastly, the biggest thing to help out, was just making sure I turned on the room lights during the day, trying to sort of mimic the sun, and then turning them off at night (and adding the towel would definately help too!) Atleast for my two guys, it got them to quiet down and sleep for atleast 30-1 hour, enough to try and give me a chance to fall asleep.