In new construction there is a heated sealant that is sprayed on the exterior wall, before the dirt is back-filled to grade.
There are people using a similar treatment on interiors. In addition to that, you may also try using a product like Auralex's Sheetblock. It is a vapor barrier as well as an acoustic dampener. Read the instructions. If you or a previous owner has sprayed silicone on the walls, some products will not work.
Paint the floor with 3 or 4 coats of a water based rubberised bitumen emulsion, then put sand/cement screed on top, or put down a layer of sand then cover this with a layer of polyethylene membrane from Lowes/Home Depot. or use the more expensive Auralex Sheetblock. It must be lapped up the walls, secured using flashing tape. Any joints in the plastic sheet should overlaped and be folded. Then cover the plastic sheet with sand/cement screed.