At one time there was a mania for learning while sleeping. People played recordings of physics lectures while they slept in hopes of learning during the brain’s down-time. Later science showed that these techniques did not work. There is a lot of memory consolidation during sleep, and certain things you do while awake can improve that process, but learning completely new material did not seem to happen during slumber.
But more recent science has shown that learning during sleep does work in one population: newborn infants. William Fifer at Columbia University in New York has shown that infants can learn social and other cues while they sleep.
Which means that the general environment for babies is important even while they sleep. And the the biggest danger from parental arguing in the home might not just be that you might wake up the baby.