My question involves business law in the state of: Illinois

We run a day spa in a rented portion of a building which our landlord owns. Our landlord has recently moved in a new tenant running a gym behind us separated only by a thin drywall wall. We voiced our concerns about noise to our landlord before the gym moved in and the landlord completely ignored them. The gym is very loud and is disrupting our business. We've had customer complaints and do not wish to loose customers and money of course. We have a pretty standard lease which does not specifically mention this situation as far as I can tell.

Do I have any legal recourse being an established business to require the landlord to soundproof our common wall or remove the new renter? It also seems to me that Elmhurst city sound ordinances are on my side since the gym's noise is an nuisance. http://www.elmhurst.org/DocumentCenter/Home/View/139

Are there any other solutions? I have 3y left in my lease. I'd prefer not to break the lease even if I have the right since we have a lot of money invested into the remodeling of this location already.

Thanks in advance,
Dave S