Is diachronic lenition a factor in the asymmetry in intelligibility between Danish and Swedish?

In this study, we investigate whether diachronic lenition is a factor in the previously found asymmetry in intelligibility between Danish and Swedish. Due to the historical process of consonantal lenition in Danish, the aspiration distinction between intervocalic, originally long, stops has disappeared. In two experiments, we tested the hypothesis that the absence of this distinction in Danish but not in Swedish results in better comprehension of Swedish intervocalic stops by Danish listeners than of Danish intervocalic stops by Swedish listeners. Our production experiment confirmed, not surprisingly, that there is no contrast for intervocalic stops in Danish, whereas there is one in Swedish. However, our perception experiment revealed that Danish listeners were not better in their perception of words with Swedish intervocalic stops than Swedish listeners were in their perception of words with Danish intervocalic stops. Contrary to the expectations of exemplar dynamics, in cross-language perception listeners did not always use their native categories in their perception of sounds of the non-native language and sometimes adjusted their native segment category boundaries to the values of the non-native language.