Do parents really become desensitized to the sounds of their kids screaming?

I'm making an effort to understand my neighbors who have twins who scream/cry constantly. I find the sounds of their kids abrasive but the parents seem not to notice it and have no sympathy towards my irritation with their kids.

Do parents really not feel bothered by the sounds of their own kids?

I have this awful feeling that I have been dealing with my neighbors in a way that lacks empathy but at the same time they are not paying me to be their baby monitor.