Concrete Block Firewalls
I don't find a firewall will eliminate sound. As a matter of fact, sometimes I smell odors like cigarette smoke or perfume and we have block on those walls. Definitely sound transmits. I hear the guy in the bathroom off my living room -- I really hate that and find it embarassing if company is over. Hear the radio in the kitchen, noise from the upstairs bathroom, talking from the adjoining den ...
I'd love to know how this could happen and how to buffer it.
These were built in the early 70's.