Short vs. Long Category Perception Affected by Vowel Quality

The paper studies the impact of intrinsic vowel duration on category perception in boundary conditions by examining the short vs. long category boundary perception in Estonian. Since the intrinsic duration of a close vowel /i/ is about 10-15 ms shorter than that of an open vowel /a/, we hypothesize that the short vs. long category boundary in /i/ occurs at a shorter duration than in the case of /a/. Twelve native Estonian subjects participated in the perception tests involving binary category decision in CV(:)CV stimuli where the duration of the primary stressed vowel was manipulated in a range from 100 ms to 190 ms embracing the short vs. long category boundary. The test results support our hypothesis and show that the differences in vowel quality, hence in intrinsic duration of vowels play a role in short vs. long category perception.