Processing German Vowel Quantity: Categorical Perception or Perceptual Magnet Effect?

The German vowel system shows a complex structure based on the interaction between vowel duration and formant structures between short and long cognates. This leads to the question how vowel duration is processed. The perception of vowel duration in German native speakers was tested by an identification test, a goodness rating and an adaptive discrimination test. The test results show a sharp boundary between the short and the long category. Furthermore, the category border was characterized by bad goodness ratings in comparison to within-category stimuli and a maximum in discrimination performance regarding subtle durational differences. These results meet the criteria of both the perceptual magnet effect and categorical perception.