Plain Speaking in Mil/Aero Audio Systems: In aerospace and defense audio systems, speech intelligibility is more critical than speech quality.

The article focuses on Speech Transmission Index (STI) and Modified Rhyme Tests (MRTs), the techniques for measuring speech intelligibility in audio systems. Topics covered include STI methodology, use of a form of automatic speech recognition by Articulation-Band Correlation (ABC)-MRT measurement, application of STI in high-noise envrionments like Public Address (PA) systems and aircraft voice announcements (VA), and use of ABC-MRT measurement for standard speech bandwidths.