Attempts to develop an efficient speech test in fully modulated noise

An earlier developed speech test with sentences in noise (Hagerman. 1982) was modified in an attempt to further increase its efficiency. The noise was thus changed to be fully modulated and the speech-to-noise ratio of each word was controlled in order to make all the words equally difficult both within and between lists. The new version was tested on 10 normal-hearing subjects. The 10 lists were equally difficult, but compared to the old material the reliability was worse, the learning effect was greater, and the slope of the intelligibility function was less than half despite efforts to maintain the quality of the test. Identical masking signals for identical words in the various lists seem to increase the learning effect. The strongly modulated noise seems to give shallow intelligibility functions for separate words and thus also for complete lists.