Development of the Russian matrix sentence test

Abstract

Objective: To develop the Russian matrix sentence test for speech intelligibility measurements in noise. Design: Test development included recordings, optimization of speech material, and evaluation to investigate the equivalency of the test lists and training. For each of the 500 test items, the speech intelligibility function, speech reception threshold (SRT: signal-to-noise ratio, SNR, that provides 50% speech intelligibility), and slope was obtained. The speech material was homogenized by applying level corrections. In evaluation measurements, speech intelligibility was measured at two fixed SNRs to compare list-specific intelligibility functions. To investigate the training effect and establish reference data, speech intelligibility was measured adaptively. Study sample: Overall, 77 normal-hearing native Russian listeners. Results: The optimization procedure decreased the spread in SRTs across words from 2.8 to 0.6 dB. Evaluation measurements confirmed that the 16 test lists were equivalent, with a mean SRT of − 9.5 ± 0.2 dB and a slope of 13.8 ± 1.6%/dB. The reference SRT, − 8.8 ± 0.8 dB for the open-set and − 9.4 ± 0.8 dB for the closed-set format, increased slightly for noise levels above 75 dB SPL. Conclusions: The Russian matrix sentence test is suitable for accurate and reliable speech intelligibility measurements in noise.

Key Words::

• Speech perception
• speech test
• speech reception threshold
• Russian speech audiometry

Acknowledgements

This work was supported by the EFRE project HurDig, and the Ministry of Science and Culture of the Federal State of Lower Saxony, and the Cluster of Excellence Grant “Hearing4all” from the Deutsche Forschungsgemeinschaft. We would like to thank the speaker Oxana Brandes and the students involved in data collection: Ekaterina Renner and Anastasia Altman. Special thanks go to Grigorij Strokin and Prof. Olga Krivnova from Lomonosov Moscow State University for providing an automatic transcriber for Russian phonemes, Dariusz Kutzner for his support by contraction of the speech material, as well as Prof. Emmerlich Kelih, Sabine Hochmuth, and Patrick Zeller for their support in phonetic analysis. We thank the editor and three anonymous reviewers for their constructive comments, which helped us to improve the manuscript. Parts of the present data were presented at the 13th Annual Congress of the German Audiological Society (DGA) in Frankfurt/Main 2010, at the 10th European Federation of Audiology Societies (EFAS) Congress in Warsaw 2011, and at the 11th European Federation of Audiology Societies (EFAS) Congress in Budapest 2013.

Declaration of interest: The authors report no declarations of interest. Birger Kollmeier serves as the scientific director of HörTech gGmbH (www.hoertech.de), a non-profit organization owned in majority by Universität Oldenburg. Copyright of the speech material is held by HörTech gGmbH.