When considering windows there are generally three options available for maximum achievable sound attenuation (reduction):
- Laminated glass (normally with a interlayer of polyvinyl butyral or PVB)
- A wider air space between the panes of glass
- Different thickness panes of glass within the insulating glass unit (IGU)
- A combination of all three.
The sound transmission class (STC) measured in decibels (dB) is the standard method of rating the sound attenuation characteristics of glass products. The STC is an average of an object’s ability to attenuate sound across the entire sound frequency spectrum. STC does not deaden information, which may be what is needed if you want to block a specific type of unwanted noise that operates on a high or low frequency. The higher the STC rating means the higher the sound attenuation properties of the window. As with the thermal propertices, the acoustic performance of windows and doors is influenced not only by the glass but also by the frame and construction of the window.