Sound Between Apts at Brevoort

As with any post war, the walls shared by the apartments will let the sound be heard from the neighbor but you can put a layer of sound-resistant drywall on the shared wall which will make it much better. You can also put a special rubber type layer 1/8th inch thick behind the layer of normal additional layer of drywall for even better soundproofing.

Search for
“AudioSeal® Sound Barrier” for rubber layer.

I just used it for mechanical closet of a very high-end Reno. Mass Loaded Vinyl is the commonly known name.

Note that the building was built in 1955 so the walls are more solid than the "60s buildings" which followed a few years later.

But if you are thinking of buying or renting there in the very near future, I think this project is going to cause a traffic nightmare/construction noise for a couple of years:
https://newyorkyimby.com/2019/12/permits-filed-for-14-16-fifth-avenue-in-greenwich-village-manhattan.html