Acoustic SpecificationsDownload PDF
The STC is a rating measuring a window's acoustic properties or its ability to reduce sound transmission. An STC rating is determined by measuring the sound transmission over a selected range of sound frequencies. The higher the number, the less sound transmitted.
The OITC rating, or Outdoor-Indoor Transmission Class is similar to the Sound Transmission Class testing, however it includes a higher range of frequencies to simulate a larger variety of potential sounds.