I’m sorry, is this snark? Why, precisely? The OP was certainly complete sentences. I know, because I wrote it. Allow me to reassure you- my writing skills are excellent.
It is pulsed, like a busy signal, but the tone does not vary in intensity. It is not as piercing a mouse as a train whistle, nor does it sound like a car honking. It is more like the “choo” of the choo-choo train, in pitch at least.
I’m also hilarious. Now, don’t everyone agree at once…
I see the supernatural link now. Has it been going on since the 1690s?
I live in salem as well. Close to the main tracks also. I heard nothing and I’m a light sleeper. If it was a train horn I would have definitely heard it as they carry for miles.
A few years ago I was getting ready to leave work after midnight. A train went past sounding the horn as it went through the crossing. The horn kept blowing. It was so loud I left early. Drove 2 miles home and went inside and it was still screaming. I listened to it for about 2 hours before I finally fell asleep. It was unbelievable. I’m guessing it stuck and the shop had to be called in. Apparently no one wanted to shut it down and drain the air tanks. Did you hear that one?
If we both hear it tonight I’ll meet you at the train. Bring a few dozen eggs 
Lol no, I didn’t hear that one, thankfully. I’ve only lived here a couple months. I’ll definitely check in when I hear it again, tho- maybe I am having auditory hallucinations! 
I live in Salem. I’m writing this as I can’t sleep at 1:30 am because of that exact train. Someone please find the answer. Everything this lady has described is true and it’s the absolute worst. Happens nearly every night. Should not be allowed unless someone is dying. I need answers
I used to live next door to a mosque in a Middle Eastern country. Didn’t take long to get used to the call to prayer, loud though it was.
It doesn’t rain often so things are not built to withstand a lot of rain. One day it did rain quite a bit, and at some point something shorted in the loud speaker at the mosque, resulting in a continuous blaring of a particularly annoying electronic sound until the morning when someone came to turn it off.
In my youth, I lived near a shunting yard in London. They were supposed to be quiet at night but I guess some people just ignored the rules.
This was in the last days of steam, so I would hear the shunting engine chuffing to the top of the “hump”, followed by a piercing scream from its whistle. Then there would be a short silence, followed by "CLANG! CLANG!.. CLANG! "clanggggggg!. as the waggons hit their respective trains.
Have you tried contacting your local authorities? Something that’s been going on for so long should be well-known to local government.
Two long blasts then a short blast then a long blast when approaching a public grade xing. Rule 14 9(l)
The Straight Dope: Required Train Horn Signals (eugene-or.gov)
I think that’s for unprotected (no gates) public xings.
Does this sound familiar?
https://www.reddit.com/r/SALEM/comments/cswo62/what_in_fresh_hell_is_this_train_that_lays_on_the/
“There are 16 at-grade highway-rail crossings from State Street north to the City limits and 6 additional at-grade crossings along Front Street NE where vehicles travel on either side of the tracks. All of the crossings have lights and gates, except the ones along Front Street. The Front Street crossings (Norway Street, Shipping Street, Hood Street, Gaines Street, Market Street, and D Street) only have stop signs and cross buck signing at the crossings. All of the crossings north of Front Street are very close together (less than ¼-mile).
If there are a number of crossings within a relatively short period of time and distance, and there are no “quiet zones” in that span, then I would assume that the mandated long-long-short-long blasts would have to be followed at each of the crossings.
Which … would suck.
But I suppose you knew that 