How Is Speech Privacy Achieved & What Is It?
The Privacy Index
Speech Privacy is a defined premise and, according to ASTM standards, you can measure Speech Privacy in regards to sound masking for SCIFs in two ways:
- Articulation Index (AI), measures how intelligible speech is
- Privacy Index (PI), measures the unintelligibly of speech
- They are both saying the same thing, just rearranging the words.
The Privacy Index defines several levels of Speech Privacy, but for a SCIF, Confidential Privacy, or a PI score of more than 95% is the only level that matters. This score is difficult to achieve, but sound masking can help get you there.
Speech Privacy’s ABC’s
The tools to improve the Privacy Index score are commonly referred to as the ABC’s:
- A – Absorb sound through wall or furniture panels, or high NRC-rated ceiling tiles
- B – Block sound through wall construction
- C – Cover over sound utilizing a high-quality sound masking technology
Many facilities focus on the A and B of speech privacy, and these two elements along will not achieve a decent Privacy Index score.
Sound Masking for SCIFs: The Ins and Outs
The C of the ABC’s is based on an introduction of background noise at a low level to the environment. Thus, intruding speech and noises are less intelligible. “White noise” is a widely used term referring to speech privacy or sound masking systems.
Sound masking technology was the realization by engineers and scientists that oral privacy is actually a matter of making speech unintelligible. In simpler terms, is each of us can’t understand what one another is saying, we have established oral privacy- even if we can still see and to some extent hear each other.
Where is the proper placement to achieve this? Answer- you mask the area where the speech is heard, not where it is spoken. This is important for the two reasons listed below: