Originally I was not planning on insulating my basement ceiling therefore I bought and installed non ic rated recessed can lights. Well, now I want to insulate my ceiling. Would it be help full at all to just insulate all the areas where there are no cans and leave the areas where the cans are installed without insulation. Will there be too much sound coming through the areas where the lights are if there is no insulation? How close can I insulate to the lights if they are non ic rated?