Design of Double Talk Sequences in Different Languages to Harmonize Third Party Listening Test Results

In [1] a Third Party Listening Test (TPLT) was introduced using pre-recorded conversations in Russian, German and English language to assess and verify the quality of eCall systems (In-vehicle Systems, IVS). The comparison of different languages shall verify the possibility for IVS manufacturers to optimize performance of their systems for the homologation tests according to MGS R55531 [2] based on different languages. First tests lead to similar results for Russian, English and German recordings for most of the tested devices and parameters [1]. Only for particular devices, showing fast switching characteristic during double talk, ambiguous results were found under double talk conditions. The double talk sequence, in particular the timing of uplink and downlink signals, was adapted for the German sequence and the test was repeated in all three languages. Furthermore two groups on test persons, naïve and expert subjects, participated in the German test session in order to verify the consistency of results between both groups. The adapted speech sequences and the results of the recent listening test are discussed here. [1] F. Kettler, S. Poschen, R. Serafimov, “Third Party Listening Test in Emergency Call Scenarios using Different Languages, DAGA Aachen, March 2016 [2] ERA-GLONASS Specification MGS R55531, In-vehicle emergency call system compliant test methods for quality of speaker phone in a vehicle, 2015