Neighbor (50sM) is making me (28F) and my roommate (24F) feel unsafe by screaming randomly.

Lived in this apartment building for a year or so. Within the last 4 months, my neighbor has developed a habit of sudden, enraged shouting. The sound travels through the walls pretty well and is pretty scary to hear when you're not expecting it. It's woken us up from sleep a few times. My roommate is more bothered by it than I am - she has a history of abuse by a loud male relative and she'll get teary-eyed sometimes after it happens. It just makes me angry.
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We recently figured out what's going on. Initially we thought me might have tourette's, or be mentally ill and maybe hallucinating? But it turns out that the family above him has two young girls who are too loud for his liking, and so when he feels bothered by them, he screams as loud as he can to get them to shut up. Sometimes we can make out words like, "IT'S SATURDAY ******ING** MORNING" and other times it's just unintelligible "NYAAAAAAAGH!!!!" He also sometimes, we think in an attempt to get back at his upstairs neighbors, will blast opera music on his stereo at full volume. The idiocy of it gets me. He's mad about a disturbance, so he creates another disturbance? One that affects the people next to him, beneath him, and above him?
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We e-mailed our building manager who said she would speak to his landlord about it. It subsided a little for a while after that, but then it started up again. I followed up a few weeks later to say it's still happening, and the building manager hasn't responded.
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I feel kind of uneasy when I see him in the hallway and the parking lot. I don't feel much like there's anything I can do about the noise. Any suggestions?
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TL;DR: Next-door neighbor (50sM) is bothered by **his** upstairs neighbor, and randomly shouts at the top of his lungs to get them to shut up. The random shouting is disruptive and upsetting. Building management hasn't been much help.


Source.