Background: For assessing a noise-induced hearing loss, the Freiburg speech test (Freiburger Sprachtest) is traditionally used to examine speech recognition in silence. However, for many years this test has been shown to have serious shortcomings. Various modern procedures in German language are available as alternatives.
Methods: The aim of the current study was to compare the Freiburg number test (FBZ) with the Göttingen sentence test (GöSa) and the Freiburg monosyllabic test (FBE) with the monosyllabic rhyme test developed by von Wallenberg and Kollmeier (WaKo), all applied in silence. Overall, 31 participants with various degrees of hearing loss were tested in this study. Speech intelligibility was determined with both monosyllabic tests at presentation levels of 60 and 80 dB SPL and for some listeners also at 100 dB SPL. The maximum intelligibility was also determined. In addition, for the combination FBZ and FBE and for the combination FBZ and WaKo, the percentage of hearing loss based on speech audiometry was calculated.
Results: The results show that both of the modern speech tests can be used as an alternative to the Freiburg speech test. Altogether the monosyllabic rhyme test leads to higher speech intelligibility than the Freiburg monosyllabic test. Therefore, a reduction of the presentation level by 15 dB is recommended if it is intended to retain the existing tables for calculating the percentage of hearing loss. Reducing the presentation level also has the advantage that measurements at 100 dB SPL are not required anymore. A level of 100 dB SPL is assessed as unpleasant by many listeners.