Epenthetic vowels in Japanese: A perceptual illusion?

In 4 cross-linguistic experiments comparing French and Japanese Listeners, we found that the phonotactic properties of Japanese (a reduced set of syllable types) induce Japanese listeners to perceive "illusory" vowels inside consonant clusters in vowel-consonant-consonant-vowel (VCCV) stimuli. In Experiments 1 and 2, a continuum of stimuli ranging from no vowel (e.g., ebzo) to a full vowel between the consonants (e.g., ebuzo) was used. Japanese, but not French participants, reported the presence of a vowel [u] between consonants, even in stimuli with no vowel. A speeded ABX discrimination paradigm was used in Experiments 3 and 4 and revealed that Japanese participants had trouble discriminating between VCCV and VCuCV stimuli. French participants, in contrast, had problems discriminating items that differed in vowel length (ebuzo vs. ebunzo), a distinctive contrast in Japanese bur not in French. It is concluded that models of speech perception have to be revised to account for phonotactically based assimilations.