Oh my God, finally someone who understands the way that I feel about those ******* swivel chairs that just squeak nonstop and it's like WHY CAN'T ANY OF YOU SIT STILL?! Grrrr!

I'm really sorry that you're having such a hard time concentrating. Honestly, I wish your professor would do a bit more about it. I raised a concern with one of my professors before about people talking and he informed me that he would intervene if he got too many complaints. Maybe, if you know anyone else in the class, you could have them complain to the professor as well? I'd definitely take her advice though and sit closer to the front. Even if you won't help you much, a little bit is better than nothing.

Is it possible for you to record the class on your laptop or anything? Of course, it'd still pick up the background noises, but if you're really feeling like you won't be able to concentrate in class, then it might be easier to just listen to the recording later when you're less frustrated about all of the distractions. Linguistics is a really bad class to not be able to hear in.

I hope you can resolve this somehow. I know how frustrating it is. Hang in there!