Privacy Index

A measure for rating the speech privacy performance of an architectural space (or lack of speech intelligibility).

Privacy Index is calculated from the Articulation Index (AI) according to the following: PI = (1 - AI) * 100%.

• A privacy level of PI > 95% represents confidential speech privacy, speech sounds can be heard but not understood.
• A PI between 95 and 80% represents normal or non-intrusive privacy, speech can be occasionally heard and understood but is generally non-intrusive.
• A PI < 80% is poor privacy, most nearby conversations can be heard and understood.

See also: Articulation Index, Masking Sound, Room Acoustics, Speech Interference Level.