Foam padding, one-eighth-inch thick, has a minimal ability to muffle the hollow sound made when walking on a laminate floor. Foam underlayment, while the least expensive, usually does not have a built-in moisture barrier to prevent moisture from seeping into your floor from below. If your subfloor is concrete or ceramic, add a moisture barrier made of sheet polyethylene. Extend the moisture barrier 2 inches up the wall. Give the rolls 8-inch overlaps and tape them into place. Foam underlayment without an added moisture barrier may be sufficient if your subfloor is above ground level and is made of wood.
Combination foam underlayment comes with an attached moisture barrier. It comes in the same thickness and has the same sound-muffling qualities as standard foam underlayment.
Cork, felt and other materials are used to make underlayments with a superior ability to muffle sound. The high-end cork underlayment is the most expensive, but it suppresses the most sound. An acoustical underlayment typically comes with an attached moisture barrier, so you can install it directly on the subfloor. If it does not come with a moisture barrier, you should lay the moisture barrier first, then the acoustical underlayment.
Vinyl-backed underlayment is marketed in the form of easy-to-install tiles that muffle noise. If you want it to block moisture, you have to seal the joints. The manufacturer of Berry laminate floors does not consider vinyl over a concrete subfloor to be sufficient to block moisture. You can install vinyl-backed underlayment on wood subflooring, though, although the wood must not contain more than 12 percent moisture for vinyl-backed underlayment to be suitable.