This is really just a chat - maybe someone has had a similar experience.
A neighbour in the block of flats is in her early 80s, widowed, retired professional.
We're not terribly friendly - she has always been a bit high-handed and I keep it polite but not chummy.
A few years ago she developed hydrocephalus, a brain condition which was successfully treated.
Recently, I have heard barking noises from her flat - not a dog, but a person. Sharp, shouty sounds. Also heard her saying four-letter words under her breath as she walked down the corridor.
Another neighbour says they hear swearing and shouting and there is no one else in the apartment.
She has some help, and is apparently in good health otherwise, but honestly, it's like living with Mrs. Rochester in the attic.