A: Many factors influence the level of sound within a building, so first let's deal with some of the easier fixes that may not necessarily have anything to do with home renovation or windows.Our sound quality expert reminds us that the entire room transmits sounds. So, everything from the studs to the drywall to the windows to the floor to ceiling ask as a giant "eardrum" to pick up and transmits any external sounds. That said, one simple fix is simply to make sure that your headboard is not resting against the wall. Breaking the connection between the wall and headboard will go a long ways towards quieting down your bedroom.
Next factor: does your bedroom have proper sound dampening qualities? By this, we mean carpeting, thick draperies (as opposed to the Venetian blinds), a sufficient amount of furniture, padding under the carpet, and so on. And while almost no one likes it anymore, the classic cottage cheese or popcorn style ceiling is also marvelous at reducing sounds.
Perhaps carpeting and drapes and popcorn ceilings do not fit with your aesthetic? There is something called Acousti-Coat Sound Reduction Paint, which is very expensive but claims to have certain sound absorbing fillers and resins that will help quiet down the sound in your room. Be careful, though: Acousti-Coat is about three times more expensive than regular interior latex paint, and I am dubious about its effectiveness.
Assuming that your condo association will agree to changes in your windows, you can upgrade to a triple paned window. Many homeowners install triple paned windows as much for their sound-deflecting qualities as for any potential energy savings. The good thing about triple paned windows is that you can duplicate the same style of window that you currently have without running afoul of your condo association.
Another thing to look at, which many homeowners rarely think about, is the type of window frame that you have. Think of it: doesn't metal transmit sound better than plastic? If you have metal framed windows, you are better off with vinyl, fiberglass, or wood framed windows, at least as far as controlling sound goes.
Another add-on that the condo association would probably not object to is to install a storm window. Storm windows are easy to put on, easy to take off, very cheap, and not very noticeable. The ultimate solution would be shutters. Real wood shutters would guarantee quieter nights, but would understandably be a hard sell to the other residents in the association.