In the end, everyone has something. Sometimes it is the nearby/distant highway, the railway, the fire brigade, a production company, a farm, the poultry farming, the well-behaved groups of children, the barking dogs, the annoying neighbor, kindergarten, school, sports field, church.
If you don’t want to hear anything at all anymore, you have to go to the desert.
Anyone who has actually heard absolutely nothing around them, not even small living creatures, buzzing, chirping or other sounds, is aware of the amount of background noise we already perceive as normal.
Hearing truly nothing is almost unsettling.
if you have indeed fixed so much on the honking of the train and cannot let it go, I would personally not buy any property/real estate but rather rent something, so that I can respond flexibly at any time if necessary.
For me, as someone not affected in this case, this reads more like a luxury problem, as I would not fear this so much or would be more allergic to other types of surroundings or human behavior.