I actually have heard the baby cry since, just a little...nothing as big as that night. I think that slapping I heard might have been a different neighbor, or not what I thought, as I haven't heard it since, and the baby's crying since has sounded completely normal.
I remember when Em was a baby, and I was sick with the flu, there was a night where she had been crying for so long, she was in near-hysterics, and I hadn't heard her because I was so sick...when I got there, she sounded much like that baby did that night...and I haven't heard it since, so I think it might have been something along those lines.
I have heard him/her minorly crying off and on since, but it now sounds like normal baby crying...not the hysterical crying I heard that night.
Ultimately, I have no proof anything happened...and I've heard the baby since, so I know he/she's okay...but I've been keeping my ears open just in case.
Thanks for asking! I continue praying...
Hugs!
Rosie*