The experiment reported in the present study was designed to compare the intelligibility of natural and LPC-vocoded linguistic stimuli presented to native and non-native speakers (listeners) of English. Subjects were 20 native speakers of English and 20 native speakers of German who were fluent in English. Three types of stimuli-the Diagnostic Rhyme Test, the Meaningful Sentences Test, and the Semantically Anomalous Sentences Test-were presented in both natural and vocoded conditions. Results revealed the following: (1) The non-native listeners performed significantly worse than the native listeners in the vocoded condition on the DRT and in the natural and vocoded conditions on the two sentence tests; (2) the effects of listening condition and test type upon response accuracy were nonadditive; (3) the non-native listeners appeared to utilize processing strategies unlike those of the native listeners; (4) the non-native listeners experienced greater recall difficulty than the natives; (5) word frequency affected response accuracy for both subject groups, though somewhat more so for the non-native than for the native listeners; and (6) unlike the native listeners the non-native listeners appeared to exhibit fatigue effects in response to vocoded speech. (Author) (kr)
