ICD 705 Acoustical Testing Considerations for SCIF and SAPF areas

We provide acoustical testing of SCIF and SAPF areas to satisfy the following parameters as detailed in ICD 705 Version 1.4:

A. Overview
1. This establishes DNI guidelines to protect classified conversations from being inadvertently overheard outside a SCIF.
2. This is not intended to protect against deliberate technical interception of audio emanations.
 
B. Sound Group Ratings
The ability of a SCIF structure to retain sound within the perimeter is rated using a descriptive value, the Sound Transmission Class (STC). To satisfy the normal security standards of SCIFs, the following transmission attenuation groups have been established:
 
Sound Group 3 – STC 45 or better. Loud speech from within the SCIF can be faintly heard but not understood outside of the SCIF. Normal speech is unintelligible with the unaided human ear.
Sound Group 4 – STC 50 or better. Very loud sounds within the SCIF, such as loud singing, brass music, or a radio at full volume, can be heard with the human ear faintly or not at all outside of the SCIF.
 
C. Acoustic Testing
1. Audio tests shall be conducted to verify standards are met. Tests may be instrumental or non instrumental as approved by the AO. Test method used shall be detailed in the CSP.
2. Instrumental Acoustic Tests:
a) Only those with training on audio testing techniques shall conduct instrumental acoustic tests
b) With all SCIF doors closed, all perimeter walls and openings (e.g., air returns, doors, windows, etc.) shall be tested along multiple points to ensure that either Sound Group 3 or 4 is met.
c) Audio test sources shall have a variable sound level output.
d) The output frequency range shall include normal speech.
e) Test speakers shall be placed six feet from the test wall and 4 feet off the floor.
f) Audio gain of the test source shall produce “loud or very loud speech” as defined by Sound Group 3 and 4 levels respectively.
g) As an alternative, instrumented testing may be performed to Noise Isolation Class (NIC) standards. Results shall comply with NIC 40 for Sound Group 3 and NIC 45 or Sound Group 4
 
Contact us today to speak with one of our consultants about your project.
You can reach us at 1-800-665-0080 or feel free to email us at project@osatusa.com

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