*STC (Sound Transmission Class) - a rating to represent how well a building partition attenuates airborn sound. The higher the STC number, the greater amount of sound that is lost. This rating targets a noise spectrum surrounding speech levels. | *STC (Sound Transmission Class) - a rating to represent how well a building partition attenuates airborn sound. The higher the STC number, the greater amount of sound that is lost. This rating targets a noise spectrum surrounding speech levels. | *STC (Sound Transmission Class) - a rating to represent how well a building partition attenuates airborn sound. The higher the STC number, the greater amount of sound that is lost. This rating targets a noise spectrum surrounding speech levels. | *STC (Sound Transmission Class) - a rating to represent how well a building partition attenuates airborn sound. The higher the STC number, the greater amount of sound that is lost. This rating targets a noise spectrum surrounding speech levels. |