"BA is not a quiet city."

That's for sure. I honestly had never been in a city as noisy as BA until I went to BA and I've been in a LOT of cities around the world. First, I rented a split-level apartment in Palermo Hollywood and which I loved, but there was noise from both slamming doors, barking dogs and loud-talking tenants along with a train that ran all throughout the night. This was in Dec 2008.

I did finally get sleep when I checked into the Melia Recoleta Plaza Hotel. I had a very nice, but odd room there in that I don't think I had a window. But, by not having a window, I had no noise and slept like a baby.

Happy Travels!

Susiesan - If a quiet night is a key requirement for you then perhaps you should consider staying in Puerto Madero, the regenerated area by the port. It is ultra modern, wide quiet streets, little traffic and, as all the buildings are modern, they should be pretty soundproof. Similar in some rsp cts to Londons Docklands area it is not the most "authentic" BA barrio but has some great restaurants nad hotels . It is also a bit out of the way but a reasonable walk to San Telmo and the Plaza Mayo. Taxis are cheap in BA but can take time if you hit the rush hours.

We looked at a lot of apartments there when we were considering settling in BA and there are some fantastic places there. I am sure some of them must be on AirBnB or one of the other dental sites

Having stayed in hotels here and there, we learned long ago that a room on a "high floor in the back" is often the one to ask for.
In BA on our visit, we stayed at the Art Suites. On a one way street in Recoleta.
The "breathing space" between all the buildings was our view, green and quiet.
When we were looking for our home, we bought an apt that had the bedrooms in the back, facing another green space and the backs of other buildings, the front of the apt faced Pueyrredon ... if you have been there, you know it is not a quiet little street.
Amazingly, the bedroom was totally silent except for the person who walked in high heels on bare wooden floors upstairs ( only one night so there were no attempts at throwing her out ) .. so keep that in mind too... take your shoes off at the door ..