I hypothesized that plosive perception contributes to speech perception of Japanese. I have noted that Shanghai speakers with the voicing contrast yet with a modest knowledge of Japanese grammar are generally higher in listening comprehension than Mandarin speakers without the voicing contrast but with a higher knowledge of Japanese grammar. In order to verify this hypothesis, I examined the relationship between the plosive perception and speech perception of the two groups. Results indicate that confusion in plosive consonants is a factor contributing to the confusion of speech perception and, especially, that confusion in voiceless plosive [t] and [k], whose frequencies are the two highest in Japanese speech, is a significant factor preventing Mandarin speakers from perceiving Japanese speech.
