Polish sentence matrix test for speech intelligibility measurement in noise

Abstract

The purpose of this study was to develop the Polish sentence matrix test (PSMT) to measure intelligibility of speech presented against a background noise. The PSMT consists of five columns containing: 10 names, 10 verbs, 10 numerals, 10 adjectives, and 10 nouns. Since each word was available as a separate sound file, it was possible to generate different sentences by juxtaposing randomly selected words taken from respective columns. This approach allows 100,000 unique sentences of a fixed grammatical structure to be generated. The speech reception threshold (SRT), i.e. the signal-to-noise ratio (SNR) providing 50% speech intelligibility and S(50), the slope of an intelligibility function at the SRT point, were shown to be -9.6 dB and 17.1 %/dB, respectively. Note that in this study dB is regarded as dB SNR, otherwise reference is given. PSMT was also evaluated using an adaptive 1-up/1-down staircase procedure in investigations with and without participation of an experimenter. No significant differences were shown for SRTs obtained in these investigations.

Development and evaluation of Polish digit triplet test for auditory screening

“…The upper limit of the 95%-confidence interval was -8.0 dB, which means that if the test is performed, the SRT above It is worth noting that mean SRT obtained for the Polish digit triplets, i.e. -9.4 dB, is considerably lower than that for the Polish sentence test, where mean SRT= -6.1 dB (Ozimek et al, 2006). In other words, in masking conditions the listeners' performance turned out to be much better when they were presented with digit triplets rather than meaningful sentences.…”

“…3 In the case of sentence tests, each utterance is presented to a given listener only once in order to avoid the learning effect (Versfeld et al, 2000;Ozimek et al, 2006).…”

“…characterized by similar and steep intelligibility functions for each list regardless of its index (Plomp and Mimpen, 1979;Nilsson et al, 1994;Kollmeier and Wesselkamp, 1997;Versfeld et al, 2000;Wagener, 2003;Smits et al, 2004;Wagener et al, 2005a;Ozimek et al, 2006). The similarity of SRT values and large S 50 implies low intra-and inter-variability of the lists, i.e.…”

“…Subsequently, 'optimal' speech elements, i.e. of relatively large S 50 and close SRT values are selected, while elements with small S 50 and SRT that deviate considerably from the remaining ones are rejected (Versfeld et al, 2000;Ozimek et al, 2006). This method also preserves the natural intonation and coarticulation.…”

“…For example, the Polish CVC and number test (Pruszewicz et al, 1994a,b), the logatome test (Brachma ski and Staroniewicz, 1999), the Corpora database (Grocholewski, 2001) and the recently developed Polish sentence test (Ozimek et al, 2006).…”