Assoc. Prof. Jan Holub Ph.D.
Future Forces Forum Future Forces Exhibition 2016 Future Soldier Systems Conference (FSSC) 2016 Military Advanced Robotic Systems (MARS) Conference 2016
Faculty of Electrical Engineering, Head of Dept. of Measurement
Czech Technical University in Prague
Low Bit-rate Coded Speech Intelligibility – Comparison of Laboratory Test Results and Results of Test with Parallel Task
POSER: A special subjective intelligibility test design and results are reported. The same sample set has been tested twice using Modified Rhyme Test (MRT)  method, first in regular laboratory environment conforming to ITU-T P.807  or ANSI/ASA S3.2 . The second test run is performed with parallel task , loading the subjects with both mental and physical load simulating more realistic field environment. The results are compared not only in terms of their reliability and statistical parameters but also with respect to their practical consequences and potential applications.
In total, 48 test subjects have participated in the test. The tested conditions are car (HMMWV) cabin noise at different levels as the background noise, the coding used is Mixed Excitation with Linear Prediction/Enhanced (MELPe) , operated at 2.4 kbit/s. The results indicate interesting opposite pair rankings of results for laboratory and simulated field environments for certain conditions, thus justifying the need for further research and standardization of dual-task based subjective tests.