I've always heard that you should continue on with all the normal noise of the household so that your baby will learn to sleep through anything. I've heard lots of people say that they did this and it worked.
I have another theory. I think that some people will sleep through anything and others will not. We're just born that way. Those who would sleep through anything end up with parents who say they never reduced the noise and thus it taught their baby to sleep through anything. Those with babies who wake at every little sound end up being quieter so that their baby will sleep.
If it were possible to actually learn to sleep through noise, I would have learned that by now. Maybe I didn't start out that way as a baby, I have no idea. But I've been told my older brother was really noisy so that makes me think that I should have started out my life sleeping through noise. But I can remember lots of naps as a little kid where I couldn't sleep because some little noise woke me up. And nowadays, as exhausted as I am most of the time, I should definitely be able to learn to sleep through noise, but nope. I wake at every little sound.
So I refuse to believe that it's through poor training that Ezra needs quiet to sleep. It's just who he is. And I believe that someday when he wakes up with babies at night, his wife will appreciate this trait that is just a natural part of who he is regardless of how hard his siblings have tried to train it out of him.
And no, it can't possibly just be that my house is exceptionally noisy. Sometimes it is and sometimes it isn't and he still can't sleep through ANY little sound.