Development and evaluation of Polish digit triplet test for auditory screening

The objective of this study was to develop and evaluate the Polish digit triplet test for speech intelligibility screening. The first part of the paper deals with the preparation of the speech material, the recording procedure and a listening experiment. In this part, triplet-specific intelligibility functions for 160 different digit complexes were determined and 100 ‘optimal’ triplets were selected. Subsequently, four statistically balanced lists, each containing 25 different digit triplets, were developed. The speech material was phonemically equalized across the lists. The mean SRT and mean list-specific slope S50 for the Polish test are −9.4 dB and 19.4%/dB, respectively, and are very similar to the data characterizing the German digit triplet test. The second part describes the results of the verification experiments in which reliability of the developed test was analyzed. The retest measurements were carried out by means of the standard constant stimuli paradigm and the adaptive procedure. It was found that mean SRT obtained with retest study was within the limits of standard deviation, in agreement with those obtained in the basic experiment.