Sound - Isolation

Sound - Isolation

from Ching Viz Dictionary of Architecture

transmission loss = a measure of the performance of a building material or construction assembly in preventing the transmission of airborne sound, equal to the reduction in sound intensity as it passes through the material or assembly when test at all one-third octave band center frequencies from 125 to 4000 Hz: Expressed in decibels, abbr.: TL

average transmission loss = a single number rating of the performance of a building material or construction assembly in preventing the transmission of airborne sound, equal to the average of its TL values at nine test frequencies.

Sound transmission class = a single number rating of the performance of a building material or construction assembly in preventing the transmission of airborne sound, derived by comparing the material or assembly to a standard frequency curve, abbr.: STC

The higher the STC rating, the greater the sound isolating value of the material or construction. An open doorway has an STC rating of 10; normal construction has STC ratings from 30 to 60; special construction is required for STC ratings above 60.

Impact noise = structure borne sound generated by physical impact, as buy footsteps or the moving of furniture.

impact insulation class = a single number rating of the performance of a floor-ceiling construction in preventing the transmission of impact noise, abbr.: IIC