In open suspended ceilings there is often the needs for speech privacy or sound blocking along with absorption. This requires a ceiling tile that has both an STC and an NRC. The STC number is a comparative number that tells the expected decibel reduction upon use of a certain product. The NRC number tells how much potentially reflective sound is absorbed or trapped. In suspended ceiling applications where there is an open plenum above multiple offices or rooms, there is usually a need to use a composite ceiling tile or lay in mass loaded vinyl barrier over existing ceiling tile.