Sometimes it's because of personal limitation (physical or mental), sometimes it's just like your superiors want you to be miserable. But since you need to work to basically just be alive, they know you won't leave or will have trouble doing so.
I want to hear your stories. I must not be alone in this.
In my case, I have to listen to recordings all day. That's the job. But the office I am in is pretty much a construction zone, and that is since I got here 5 or 6 months ago (and doesn't seem likely to be done soon). So in the middle of the work day, you'll get loud saw noises (barely any insulation), hammering, etc. For the record, I don't blame builders for doing their jobs, it's literally what they are there to do; the problem is doing audio-intensive work in a workplace that is already unacceptable to do accounting work in. Add to that any mental limitation and you are setting people for failure. Doesn't seem to bother management, since they work from home anyway.