Outdoor-Indoor Transmission Class

Outdoor-Indoor Transmission Class (OITC) is a standard used for indicating the rate of transmission of sound between outdoor and indoor spaces in a structure. It is based on the ASTM E-1332 Standard Classification for the Determination of Outdoor-Indoor Transmission Class. An alternative similar standard for determining the rate of acoustic isolation of a separation between spaces is STC. While STC is based on a noise spectrum targeting speech sounds, OITC utilizes a source noise spectrum that considers frequencies down to 80 Hz (Aircraft/Rail/Truck traffic) and is weighted more to lower frequencies.


  1. ASTM International:
  2. Viraconsulting Glossary:
Search another word or see outdooron Dictionary | Thesaurus |Spanish
Copyright © 2015 Dictionary.com, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature