To give you an idea of the various STC levels, let’s take a look at a scale from 25 to 55. Remember, STC is NOT the LEVEL of sound; it is the amount of privacy afforded.
Still confused? This might help:
An STC rating of 25, is where normal speech can easily be understood. If you want quiet/privacy, an STC rating of 25 is not ideal. If you’re just trying to divide up physical space, this may work for you. A storefront where after-hours security is needed but the products inside are still allowed to be seen using Frameless GlassWall for example.
An STC rating of 55, is where shouting cannot be heard. If you want total quiet/privacy, an STC rating of 55 is great. If you are wanting to divide up physical space and keep those spaces private, this is perfect. Think meeting rooms utilizing operable panels for example.
Listed below are some typical building items and materials to give you an even better idea how the typical operable partition compares.