I lived in one, a waller type, built just after ww1. If it turns out to be that type although it doesn't look like it from the pic... RUN!
No soundproofing whatsoever, in fact it amplified every tiny sound 10x louder. Could hear every word, fart, sneeze, cough from next door no matter what room or floor I was on as if they were stood right next to me. The impact noises are horrendous. Next door would come in, drop their shoes or bag of shopping on the floor and it sounded like they were taking a sledge hammer to the wall. After 4yrs of sleep deprivation I moved.