One thing that my mom did (I didn't have kids) is not be completely silent when the baby is sleeping. That's how you create light sleepers. Make noise, have the TV on, play music, talk normally, don't whisper. She ran a daycare for about 10 years and that was one of the things she did when the babies were sleeping, was just have regular noise levels. Made a judge difference. I sleep like the dead and noises generally does not wake me up.