Acoustic protection keeps classified conversations from being overheard by someone standing outside the SCIF. It is a requirement for any SCIF where SCI is discussed.
The governing statements:
ICS 705-1: SCIFs that require SCI discussions "shall provide acoustic protection to prevent conversations from being inadvertently overheard outside of the SCIF."
Tech Spec Chapter 9 overview (as quoted by practitioner sources): "The acoustic protection guidelines … are designed to protect classified conversations from being overheard outside a SCIF and not intended to protect against purposeful technical interception of audio communications."
What that means in practice:
Acoustic protection does
Acoustic protection does not
Stop a passer-by, neighbor or cleaner from understanding speech through walls, doors, windows and ducts
Defeat laser microphones, contact microphones, implanted devices or other deliberate technical collection
Set a measurable performance level (Sound Group 3 or 4) for the perimeter
Replace TSCM, TEMPEST countermeasures or PED controls
Apply to every discussion area, including conference and VTC rooms
Apply to areas the AO has declared non-discussion areas (UFC adds "and protected by IDS")
Technical interception is handled by other disciplines: technical surveillance countermeasures (TSCM), TEMPEST countermeasures directed by the CTTA, and controls on portable electronic devices.
Most SCIF acoustic confusion comes from two ratings that sound similar but measure different things.
STC in one paragraph.
A laboratory plays sound on one side of a test specimen and measures how much gets through at a range of frequencies (ASTM E90). Those measurements are fitted to a standard curve to produce one number (ASTM E413). A wall with a higher STC lets less speech through. SCIF perimeters are specified at STC 45 (Sound Group 3) or STC 50 (Sound Group 4).
NIC in one paragraph.
A trained tester measures sound levels on both sides of an as-built partition in the finished building (ASTM E336). The result includes every path sound can take: through the wall, over it through the ceiling, under the door, through ducts and through electrical boxes. Those are called flanking paths. The field result is rated as NIC. The Tech Spec uses NIC 40 for Sound Group 3 and NIC 45 for Sound Group 4.
Why the numbers differ.
Rating
Measured where
Includes flanking paths?
Typical use in a SCIF project
STC
Laboratory
No
Selecting walls, doors, windows and assemblies
NIC
Finished building
Yes
Instrumented acceptance testing
A product sheet that says "STC 50" does not guarantee an NIC 45 result in your building. That gap is why DoD criteria require components rated higher than the perimeter target.
The Tech Spec defines acoustic performance as Sound Groups. SCIFs use Sound Group 3 or Sound Group 4.
Attribute
Sound Group 3
Sound Group 4
Rating
STC 45 or better
STC 50 or better
Descriptor (Tech Spec, as quoted)
"Loud speech from within the SCIF can be faintly heard but not understood outside the SCIF. Normal speech is unintelligible with the unaided human ear."
"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 the SCIF."
Field (instrumented) equivalent
NIC 40
NIC 45
Lab-tested components (UFC 3-4.3.3)
Assemblies tested per ASTM E90 to no less than STC 50
No less than STC 55
Typical wall
Wall A: three layers 5/8 in. gypsum board (one outside, two inside)
Four layers (two each side), per UFC description
Test loudness
"Loud" speech
"Very loud" speech
Reading the descriptors.
Sound Group 3 protects against normal and loud conversation. Someone outside may hear that people are talking but should not understand the words.
Sound Group 4 protects against amplified sound: speakerphones, video teleconference audio, presentation systems. Even very loud sound should be faint or inaudible outside.
Relationship to wall types.
Tech Spec Wall A is designed for Sound Group 3. The Tech Spec (as quoted by practitioners) says a perimeter built to Wall A, B or C, or of brick, concrete or other substantive material, with acoustically treated penetrations, should provide Sound Group 3. Reaching Sound Group 4 usually takes added board layers or laminated gypsum board, better door assemblies, and more careful treatment of ducts and penetrations.
Sound Group assignment is room by room, not just building by building. Most SCIFs have a Sound Group 3 perimeter and one or more Sound Group 4 rooms inside it.
Space
Sound Group
Source
SCIF perimeter (default)
Sound Group 3: "A minimum of Sound Group 3 (STC 45 or better) for the perimeter unless additional protection is required for amplified sound."
UFC 4-010-05 §3-4.3.2
Conference rooms and areas with amplified audio, such as VTC
Sound Group 4: rooms "where amplified audio is used such as video teleconference (VTC) equipment … must meet Sound Group 4 (STC 50 or better)"
UFC 4-010-05 §3-4.3.2
Amplified conversations (Tech Spec wording as quoted)
STC 50 for "amplified conversations, such as conference centers, video teleconference (VTC) rooms"
Tech Spec Ch. 9 via practitioner
Type II Compartmented Area (discussion room)
"must meet existing sound transmission class (STC) requirements per ICS 705-1"
Tech Spec 2.C.2.b
Rooms with amplified audio for classified information
Treated to Sound Group 4 / STC 50
Fixed Facility Checklist, Acoustics section
Declared non-discussion areas
Door acoustic requirement does not apply (UFC adds "and protected by IDS")
Tech Spec 3.E.5; UFC 3-4.6
Design practice.
Zone early. Mark every room on the floor plan as Sound Group 3, Sound Group 4 or non-discussion before walls are detailed.
Interior Sound Group 4 rooms need their own rated walls, doors and duct treatment, even though they sit inside the SCIF.
Plan for change. An end-user practitioner recommends designing all discussion areas to Sound Group 4, so a room that later gets VTC or a speakerphone does not need a retrofit.
The single most useful acoustic idea for a SCIF team is that the field result is almost always lower than the lab rating of the parts.
Where performance is lost.
Flanking path
How sound escapes
Deck flutes and top-of-wall gaps
Over the wall through open voids above the top track
Door perimeter
Gaps at the head and jambs, missing or misadjusted drop seals, doors that do not close fully
Ducts and returns
Through the airstream when silencers or Z-ducts are missing; through open plenum returns
Electrical and data boxes
Back-to-back or recessed boxes create a short path through the wall
Unsealed penetrations
Around conduit, pipe and cable where sealant is missing
Board and insulation
Unstaggered joints, missing sealant at tracks, sagging or unfastened insulation
The DoD margin.
UFC 4-010-05 builds the loss into the specification:
Perimeter target
Required lab rating of components and assemblies
STC 45 (Sound Group 3)
No less than STC 50 per ASTM E90 (UFC 3-4.3.3, 3-4.6.1)
STC 50 (Sound Group 4)
No less than STC 55 per ASTM E90 (UFC 3-4.3.3)
The 5-point margin is not a safety factor you can spend. It exists to absorb normal construction imperfections. A project that also leaves an untreated flanking path will fail regardless of the margin.
The Tech Spec requires the perimeter to be tested so the AO can confirm the Sound Group is met. How that testing is done is an AO decision.
The Tech Spec requirement (Ch. 9.C, as quoted).
"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."
Two kinds of test.
Test type
What it is
Rules (as quoted)
Audio (non-instrumental)
Subjective listening tests: a sound source inside, a listener outside at the perimeter
"All non-instrumental tests must be approved by the AO."
Instrumental
Calibrated measurement of sound levels on both sides, producing an NIC result
"Only those with training on audio testing techniques shall conduct instrumental acoustic tests." Results: "NIC 40 for Sound Group 3 and NIC 45 for Sound Group 4."
What practitioners report.
One security consulting firm reports that instrumented NIC testing is often not required. AOs frequently accept design review plus audio checks when construction is correct.
A test-equipment vendor reports that field test duration ranges from hours to days depending on the size of the facility and ambient noise, and that the AO specifies the required rating.
Preparing for either test.
Finish construction, including door seals, closers, ceiling tiles and all penetration sealant.
Run HVAC in its normal operating mode.
Identify every test point: each wall segment, door, window, duct and return.
Have the GC and door hardware installer available to adjust seals if a location fails.
When the AO calls for instrumented acoustic testing, the Tech Spec (Chapter 9, as quoted by practitioner sources) sets the basic geometry and sound level.
Parameter
Requirement (as quoted)
Who tests
"Only those with training on audio testing techniques shall conduct instrumental acoustic tests."
Speaker distance from wall
6 ft from the test wall
Speaker height
4 ft above the floor
Sound source
Audio source with variable output covering normal speech frequencies
Output level
Gain set to produce "loud" speech for Sound Group 3 or "very loud" speech for Sound Group 4
Test locations
All perimeter walls and openings, along multiple points, with all SCIF doors closed
Pass criterion
NIC 40 for Sound Group 3; NIC 45 for Sound Group 4
Field method
ASTM E336 measurement, rated per ASTM E413
How a typical test runs.
The tester places the speaker 6 ft from the wall and 4 ft above the floor, facing the wall under test.
The source is calibrated to the loudness associated with the room's Sound Group.
Sound levels are measured on the source side and the receiving side of the perimeter using the field method (ASTM E336).
The tester repeats the measurement at multiple points along each wall and at each door, window, duct and return.
Results are rated and compared with NIC 40 or NIC 45.
What causes test-day failures.
Ambient noise outside the SCIF high enough to interfere with measurement.
A door that was never adjusted after seals were installed.
HVAC returns and supply ducts that bypass the wall.
Most acoustic performance is decided by how the perimeter wall is framed, insulated, boarded and sealed.
Primary requirements.
Detail
Requirement
Source
Wall height
True floor to true ceiling, finished and painted full height
Tech Spec wall figures; UFC 3-4.4
Board layers (STC 45)
Three layers 5/8 in. GWB: one outside, two inside
Tech Spec Wall A
Board layers (STC 50)
Four layers, two each side (UFC description)
UFC 3-4.4.2
Laminated board
"one layer of factory laminated GWB meeting ASTM C1766" may enhance attenuation
UFC 3-4.4.3
Joint staggering
Stagger GWB joints on opposite sides so they are not on the same stud
UFC 3-4.4.2; Tech Spec Wall A
Insulation
3-1/2 in. sound attenuation material "fastened to prevent sliding"; use fibrous insulation
Tech Spec Wall A; UFC 3-4.4.4
Sealant
"Seal gaps on both sides with a non-hardening caulk so the acoustical rating of the wall is maintained"; top and bottom track bedded in acoustic sealant
UFC 3-4.4.5; Tech Spec Wall A
Utilities
Surface mounted, raceway or furred wall on treated perimeter walls; no recessed boxes
Tech Spec 3.G.5; UFC 3-4.4.7
Penetrations
Seal both sides with acoustical foam or sealant, finished to match
UFC 3-4.11.3
Sequence that protects the result.
Bed the top and bottom track in sealant before studs go in.
Fill deck flutes and voids at the top of the wall.
Install and fasten insulation so it cannot slide.
Hang board with staggered joints and seal perimeter edges of each layer.
Seal every box, conduit and pipe penetration on both sides.
Walls are rarely the reason a SCIF fails acoustically. Doors, glazing and ductwork usually are.
Doors.
Use STC-rated door assemblies: door, frame, seals, threshold and drop seal tested together (UFC 3-4.6.1).
Lab rating no less than STC 50 for an STC 45 perimeter, and STC 55 for an STC 50 perimeter (UFC 3-4.6.1, 3-4.3.3).
Cam-lift hinges for acoustic door assemblies (UFC 3-4.6.6).
A vestibule is recommended "to preclude visual observation and enhance acoustic protection" (Tech Spec 3.E.5; UFC 3-4.6.9).
Windows.
Windows "shall provide visual and acoustic protection" (Tech Spec 3.F.2).
The Fixed Facility Checklist asks whether windows are acoustically protected.
Glazing is frequently the acoustic weak element. Secondary interior glazing, laminated acoustic glass or infill walls are common approaches. Test results govern.
Ducts and air paths.
Treatment
Source
"All vents and ducts shall be protected to meet the acoustic requirements of the SCIF."
Tech Spec 3.G.7
"Provide sound baffles (duct silencers) or (Z) Duct Penetrations"
UFC 3-4.13
"In lieu of acoustical duct liner, provide double wall acoustic duct"
UFC 3-4.13
Z-ducts "can increase the above ceiling space requirement"
UFC 3-4.2
Baffle "backpressures … may significantly impact the HVAC system design"
UFC 3-4.13
The Tech Spec provides an example Z-duct detail. A Z-duct forces sound to change direction as it passes through the perimeter, losing energy at each turn.
Sometimes a perimeter cannot reach the required Sound Group through construction alone: an existing window that cannot be removed, a duct that cannot be rerouted, or a wall shared with a space the owner does not control. The Tech Spec (Chapter 9.E, as quoted by practitioner sources) allows mitigations. UFC 4-010-05 §3-4.3.4 directs designers to the Tech Spec for sound masking.
The three mitigation options.
Mitigation
What it does
When it fits
Structural enhancements
Add mass, layers, secondary glazing, better seals or duct silencers to the weak element
The weak point is physical and accessible
Perimeter stand-off distance
Create a protective zone that keeps unauthorized persons from reaching a listening position near the weak point
Adjacent space can be controlled, such as a locked corridor or controlled office area
Sound masking
Introduce sound at the weak path so escaping speech is unintelligible
The weak path cannot practically be rebuilt
How to use them.
Build correctly first. Masking and stand-off are mitigations for an identified weakness, approved by the AO. They are not substitutes for correct perimeter construction.
Identify the specific path. Mitigation targets a door, window, duct or wall segment, not the whole SCIF.
Get AO approval. The AO decides whether the mitigation is acceptable and how it is documented.
Expect scrutiny. Masking systems are subject to TSCM evaluation.
Trade-offs.
Stand-off depends on continued control of the adjacent space. A lease change or new tenant can erase it.
Masking adds equipment that must be maintained, kept on, and kept free of prohibited features.
Structural fixes cost more up front but do not depend on operations.
When the AO approves sound masking, the Tech Spec (Chapter 9.E, as quoted by practitioner and vendor sources) sets rules for where the transducers go, how loud the system runs, and what the sound source may contain.
Topic
Requirement (as quoted)
Speaker and transducer placement
"Speakers/transducers shall be placed close to, or mounted on, any paths that would allow audio to leave the area, including doors, windows, common perimeter walls, vents/ducts"
Doors and windows
Speakers at the aperture, with sound directed away from the conversation
Volume
"determined by listening to conversations outside the SCIF or area to be protected, and the speaker volume adjusted until conversations are unintelligible"
Sound source generator
"Sound-source generators shall be permanently installed and not contain an AM/FM receiver and shall be located within the SCIF"
Recording capability
Any generator able to record ambient sound "shall have that capability disabled"
Wiring
"Wires and transducers shall, to the greatest extent possible, be located within the perimeter of the SCIF"
Acceptable sources (per practitioner summary)
An audio amplifier with a standalone computer that has no network connection, or an amplifier with a CD or digital audio player
Evaluation
Masking systems are subject to TSCM evaluation
What this rules out.
Commercial masking systems with built-in radio tuners.
Network-connected or IP-controlled masking controllers, and products with Bluetooth or wireless features, unless the AO and CTTA approve them.
Portable or plug-in noise generators that can be moved or unplugged.
Sound sources located outside the SCIF feeding transducers inside.
Integrator checklist.
Get written AO approval identifying each path to be masked.
Select equipment with no receiver, no recording capability and no network or wireless features.
Mount the generator permanently inside the SCIF.
Run transducer wiring inside the perimeter.
Set volume by listening outside until speech is unintelligible, and document the setting.
Sound systems inside a SCIF create two acoustic problems: loud sound that must be kept in, and wiring that can carry sound out.
Keeping amplified sound in.
Rooms with amplified audio (VTC, conference audio, presentation systems) need Sound Group 4 (UFC 4-010-05 §3-4.3.2).
The Fixed Facility Checklist treats rooms with amplified audio for classified information to Sound Group 4 / STC 50.
Microphones and speakerphones must be disabled or AO-approved, and remote room monitoring must be disabled (Fixed Facility Checklist, telephone and call-answering questions).
Keeping audio from leaking out through wiring.
The Fixed Facility Checklist asks whether public address, music or emergency notification systems use "fiber isolation, self-amplified speakers, other method to ensure no audio back feed from the system." Systems that originate outside the SCIF need special design and approval.
System
Acoustic concern
Direction
VTC and conference audio
Loud sound through walls, doors and ducts
Sound Group 4 construction
Public address or background music
Speaker wiring carries audio out; speakers can act as microphones
Items 1–8 are drawn from practitioner and consultant experience. Items 9–10 are derived from the primary requirements. Each is tied to the requirement it breaks.
#
Failure
Requirement it breaks
1
Walls stop at the drop ceiling, or deck flutes above the top track are left open
True floor to true ceiling; sealant at top of wall (Tech Spec wall figures; UFC 3-4.4)
2
Door assemblies with missing or misadjusted drop seals, gaps at head and jambs, mixed untested components, or doors that do not close fully on the closer
UFC 4-010-05 §3-4.3.4 positions masking as a mitigation used "when normal construction and baffling measures have been determined to be inadequate." The Tech Spec lists alternatives alongside it: structural enhancement with "high-density building materials," and a perimeter fence or protective zone that provides stand-off distance (Chapter 9.E, public copy). Sound Group 3 corresponds to STC 45 and Sound Group 4 to STC 50.
Property
STC-rated construction
Sound masking system
What it does
Blocks sound transmission through the assembly
Adds sound at a leakage path so escaping speech is unintelligible
How it is measured
Sound Group and STC, checked by acoustic testing
Volume "set and fixed" after listening outside until conversations are unintelligible
Depends on operations
No; the wall works unpowered
Yes; it must stay on, at its set level, and be maintained
Adds equipment to the SCIF
No
Generator, amplifier, transducers and wiring
Inspection exposure
Acoustic testing
"subject to review [inspection] during TSCM evaluations"
Approval
Built to the Tech Spec design
AO approval for an identified weakness
Typical failure
Construction defects
Unplugged, volume changed, prohibited features
What this means for a project (derived)
Design to the Sound Group. Masking is not a line item that lets a thinner wall pass. Use it where a specific path, such as an existing window or a duct that cannot be rerouted, cannot practically be built out.
Name the path. An AO approval for masking should identify the door, window, wall segment or duct being mitigated.
Count the operating cost. A masking system is a permanent piece of equipment inside the SCIF that the site must keep running and keep free of prohibited features for the life of the accreditation.
A SCIF masking system has three parts: a sound source, an amplifier, and speakers or transducers that put the sound onto leakage paths. The Tech Spec (Chapter 9.E, public copy) describes them this way: "Sound masking devices, in conjunction with an amplifier and speakers or transducers, can be used to generate and distribute vibrations or noise."
Component
Where it goes
Rule (Tech Spec 9.E, public copy)
Sound-source generator
Inside the SCIF, permanently installed
"Sound-source generators shall be permanently installed and not contain an AM/FM receiver and shall be located within the SCIF."
Recording capability
Disabled
A generator able to record "shall have that capability disabled"
Amplifier
With the generator, inside the SCIF
Part of the approved source configurations below
Speakers or transducers
On or near each leakage path
"placed close to, or mounted on, any paths that would allow audio to leave the area, including doors, windows, common perimeter walls, vents/ducts"
Wiring
Inside the perimeter
"Wires and transducers shall, to the greatest extent possible, be located within the perimeter of the SCIF."
Output level
Above speech
"Speakers/transducers must produce sound at a higher level than the voice conversations within the SCIF."
Volume control
Fixed
"Once the speakers or transducers are optimally placed, the system volume shall be set and fixed."
Acceptable sound sources listed in 9.E
"Audio amplifier with a standalone computer (no network connection)"
An amplifier with a CD, cassette, digital audio or DAT player
An "integrated amplifier and playback unit"
"a noise generator or shift noise source generator using either white or pink noise"
Reading the rules together (derived)
The architecture is self-contained: source, amplifier and wiring all live inside the perimeter, and nothing receives signals from outside.
"Permanently installed" rules out portable or plug-in generators used as the approved system.
"Set and fixed" means the volume control should not be something occupants can turn down during a quiet meeting.
Every cable that leaves the SCIF, even for a single transducer, is a perimeter penetration for CTTA review and acoustic sealing.
The default is simple: generator, wiring and transducers stay inside the SCIF. The Tech Spec (9.E, public copy) allows one named exception, and it comes with conditions.
The text. "If the AO determines risk to be low, a speaker may be installed outside the SCIF door if the following conditions are met: The cable exiting the SCIF shall be encased within rigid conduit."
Condition
What it requires
Who decides
Risk determination
The AO determines the risk to be low
AO
Location
A speaker outside the SCIF door
AO
Cable protection
The cable leaving the SCIF is "encased within rigid conduit"
Specified by designer; inspected
Everything else
Generator and remaining wiring stay inside
Tech Spec 9.E
Why a door gets special treatment (derived). Doors are among the weakest acoustic points in a perimeter. A speaker in the corridor directly outside puts the masking sound where a listener would stand. The rigid conduit protects the one cable that now leaves the SCIF.
Installation points (derived from related rules)
Treat the cable as a perimeter penetration: seal both sides and finish to match the adjacent wall (UFC §3-4.11.3).
Bring it through the planned single point of entry where practical, labeled with its purpose and destination (UFC §3-4.19).
Leave no junction box, splice or accessible terminal on the uncontrolled side.
Include the conduit and speaker on the drawings submitted to the AO and CTTA.
What 9.E does not address. Corridor ceiling speakers away from the door, landlord or building-wide masking systems, and masking sources located outside the SCIF are not covered by this exception as read. Treat any of them as a separate AO and CTTA decision.
The Tech Spec allows "speakers or transducers." They do different jobs, and a good design uses each where it fits.
Speakers move air. They fill air paths: plenums, ceiling voids, raised floors and ducts.
Surface transducers vibrate the structure they are mounted on: door frames, studs, glazing, duct walls and pipes. The building element itself becomes the emitter.
Leakage path
Typical device
Placement rule or note
Source
Doors
Transducer on the frame, or a speaker at the aperture
"close to the aperture… sound projected in a direction facing away from conversations"
Tech Spec 9.E (public copy)
Windows
Transducer on the glazing or frame
Same aperture rule as doors
Tech Spec 9.E
Common perimeter walls
Transducers on the wall structure
Placement that "optimize[s] the acoustical protection"
Tech Spec 9.E
Vents and ducts
Speaker in the duct or plenum, or transducer on the duct wall
Must cover the path where it leaves the area
Tech Spec 9.E; derived
Raised floors, drop ceilings
Speakers sized for volumes
SpeechMask markets a Volumetric Speaker for "raised floors, drop ceilings"
Vendor
Door frames, walls, windows
High-output surface transducer
SpeechMask markets Heavy Emitter transducers for "door frames, walls, and windows"
Vendor
Design points (derived)
Map every path first. List each door, window, shared wall segment, duct and plenum on the drawings, then assign a device to each.
Aim away from the room. At apertures, the sound faces away from the conversation so it masks the outside listener, not the meeting.
Mount inside where possible. Transducers on the SCIF side of a door frame or wall keep wiring inside the perimeter.
Don't damage the barrier. Mounting must not puncture acoustic seals, RF shielding or perimeter hardening layers. Use surface mounts or approved brackets.
Keep ducts accessible. Devices inside ductwork need a way to be inspected, since the system is subject to TSCM review.
Most modern commercial masking platforms are built for open offices. They network, they take paging and music feeds, and they are managed from a browser. Those are useful features in an office and the wrong starting point for a SCIF.
The contrast. Tech Spec 9.E (public copy) lists "Audio amplifier with a standalone computer (no network connection)" among acceptable sound sources, and requires generators without an AM/FM receiver and with recording disabled. Compare the published features of one current commercial controller:
Feature (Cambridge Sound / Biamp Qt X 300, per vendor)
SCIF concern (derived)
"Dual network ports (media / control)"
A network path from a device inside the SCIF; the Tech Spec source example is "no network connection"
AVB/Dante audio networking
Audio carried over a network, potentially across the perimeter
Web interface
Remote configuration, including of the volume that must be "set and fixed"
"Two audio inputs for paging and music"
A paging feed ties the masking system to a PA system and raises the audio back-feed question
TAA compliant
A procurement attribute, not a security approval
None of this makes the product unacceptable by itself. It means the configuration has to be reviewed by the AO and CTTA before it is proposed, and the review will focus on exactly these interfaces.
Questions to answer in writing before proposing any controller (derived)
Does the unit contain a radio receiver, Bluetooth or Wi-Fi? RF transmitters need CTTA evaluation and AO approval (ICS 705-1 §G.2.a).
Can it record or capture audio? If so, can that be disabled as 9.E requires?
Which network and audio ports exist, and can they be physically disabled or left unconnected while the system still runs?
How is the volume locked after commissioning?
Where are the paging and music inputs connected, if at all? The Fixed Facility Checklist asks for "fiber isolation, self-amplified speakers, other method to ensure no audio back feed" on PA and notification systems.
The table repeats only what vendor pages reviewed for this knowledge base state. It is not an endorsement, and no masking product is "ICD 705 certified." The AO approves the installed system as part of the facility.
Vendor or line
Verified from vendor pages
Cautions
SpeechMask (joint venture of Intelligent Devices, Inc. and Transformational Security, LLC)
SpeechMask generator; Heavy Emitter transducers for "door frames, walls, and windows"; Volumetric Speaker for "raised floors, drop ceilings"; Voice Sentry 1 portable unit for "doors, windows, and ducts"; "40 units per master, driving 320 emitters per master"; EAR99
The website quotes Tech Spec 9.E, but the product page does not state network, recording or receiver characteristics. How a portable unit fits the "permanently installed" generator rule is an AO question.
Cambridge Sound (Biamp) Qt / Qt X (Qt X 300, 600, 800, 805)
Government page lists SCIFs as an application; Qt X 300 has dual network ports, AVB/Dante, a web interface, paging and music inputs; TAA compliant
The government page cites DCID 6/9. Check its STC wording against the current Tech Spec. Network and paging interfaces need AO/CTTA review.
Lencore
A "SCIFs and Security Sensitive Areas" application page
No product-level SCIF specifications on that page
K.R. Moeller / LogiSon; Soft dB
Networked office masking
No SCIF or ICD 705 mention on the pages reviewed
What to request from any masking vendor (derived)
A written compliance letter addressing the 9.E source rules: no AM/FM receiver, recording disabled or absent, permanent installation, and the network status of the configuration offered
A port-by-port interface list with disabling methods
Transducer and speaker mounting details that do not puncture the perimeter or RF shield
A masking system is only as good as its commissioning record. The inspector and later TSCM teams need to see where each device is, why it is there, how loud it runs, and that nothing prohibited is attached.
Commissioning sequence (derived; public level)
Confirm approval. Have the AO's written approval identifying each path to be masked.
Verify the equipment. Check the installed generator against the 9.E rules: permanently installed, inside the SCIF, no AM/FM receiver, recording disabled, no unapproved network connection.
Walk every path. Confirm a device is installed at each approved door, window, wall segment and duct, with wiring inside the perimeter or in rigid conduit where the door exception applies.
Listening test. With loud speech inside the room, listen outside at each path. Raise the level until conversations are unintelligible, which the Tech Spec describes as the basis for setting volume.
Set and fix. Lock the volume at that setting, as 9.E requires ("set and fixed").
Record. Document the final setting and the conditions of the test.
Record
Contents
Why the inspector wants it
Approval
AO approval naming masked paths
Shows masking is an approved mitigation
Equipment list
Make, model and firmware of generator, amplifier and transducers; manufacturer compliance letter
Confirms no receiver, recording or network features
Device plan
Floor plan with each device and cable route
Supports TSCM review
Penetrations
Any cable leaving the SCIF, its conduit and seal details
Perimeter integrity
Commissioning log
Test positions, final volume setting, date, who performed it
Proves "set and fixed"
Maintenance plan
Who checks the system is on and unchanged
Keeps the mitigation working
Handling (derived). Device plans and commissioning logs describe a specific facility's acoustic weaknesses. Control them as the SSM directs, and keep them out of bid portals and marketing material.
