Volume. My first wife and I lived next to a very noisy woman and her daughter, who was about seven or so. Child was named Karen, and even now, 55 years on, I can visualise the mother screeching ‘KAAARREEEEEENNN’ at about 97 decibels. Don’t know if there was a father in residence; if so never saw nor heard him.
The TV and/or radio was always loud. The houses were cheap and nasty 1930s semis, so flimsy that in the still of the night, we could hear Karen patter across to the bathroom and use the toilet. That wasn’t their fault, but the loud TV and radio were. One weekend day I prepared a tape loop of the really noisy bit of the 1812 Overture, the bit with the cannons, left it playing on my trusty reel-to-reel, with the speaker up against the party wall, and went out for about three hours. Whereas gentle comment had been water off a Duck’s back, this time the hint was taken.
Thankfully, we only had the place on a twelve months rent
Mike