Evaluation of internationally compatible speech test in noise for the pediatric population

Background: Reliable and internationally compatible speech audiometry in noise for adults as well as for the pediatric population is of great importance for hearing diagnostics and rehabilitation. This contribution reports evaluations of the simplified Matrix sentence test (shortMatrix) in German, Italian, and Russian for internationally comparable and accurate speech audiometry in children. Material and methods: The shortMatrix test consists of a 21-word base matrix from which speech phrases of a fixed structure are generated (like ‘eight red windows’). For all languages, 7 out of 10 numerals, adjectives, and nouns were selected from the standard version of the Matrix test taking into account words the children are familiar with. Furthermore, the phoneme distribution of the base matrix was compared to the language-specific phoneme distribution. Each of the ten test lists consists of 14 speech phases and each word is represented exactly two times in a list. First, speech recognition measurements were conducted with young, normal-hearing adults to prove the equivalency of the test lists and to obtain reference data for adults. Next, the test was evaluated with normal-hearing children in order to establish reference data for children from 5 to 10 years old and assess test-retest reliability of the test. In total, 50 young normal-hearing adults (20 in Italy and Russia, and 10 in Germany) and 203 normal-hearing children participated in the experiments (95 in Italy, 63 in Russia, and 45 in Germany). Results: Evaluation with adults: in each language, the test lists are equivalent in intelligibility with a standard deviation in speech reception threshold of 0.2 dB. Training session requires presentation of 1 list only. Evaluation with children: in each language, the slope of the test-specific intelligibility function is slightly lower than for adults and ranges from 9 %/dB for German to 12.7 %/dB for Russian. Children require about 2-dB better signal-to-noise ratio than adults to correctly recognize 50% of presented speech material. Test-retest reliability is comparable across different age groups of children and between children and adults. Conclusions: The shortMatrix test was shown to be a reliable test for speech intelligibility measurements in noise for children.