Speech Intelligibility Testing – STI and CIS

On-Site Acoustic Testing conducts speech intelligibility testing for a variety of purposes including:

  • Proof of unintelligible speech index scores (CIS) in secure areas such as SCIF and SAPF areas (privacy applications)
  • Proof of effectiveness of white noise systems for noise masking systems in secure areas such as SCIF and SAPF areas (privacy applications)
  • Verification of speech intelligibility for evacuation systems (fire and emergency) both indoor and outdoor
  • Verification of speech intelligibility for conference rooms, classrooms, and auditoriums

Speech intelligibility may be reported using two alternative measurement scales which are:

  • CIS (Common Intelligibility Scale) – which is used for government and military applications
  • STI (Speech Transmission Index) – which is used for most other applications

Both methods of speech intelligibility testing involve using pre-recorded sounds which are then amplified and measured within the room, or in adjacent spaces (for privacy applications).

We utilize industry standard equipment from Liechtenstein-based manufacturer NTI to conduct this testing.

To learn more, simply use the convenient form located below:

Please list the city and state where testing will take place.
List the project criteria and type of testing required, if known (noise survey, dosimetric, AIIC, ASTC, NIC, air quality, etc.)

Or call one of our testing specialists at 1-800-665-0080