Relative contributions of consonants and vowels to Mandarin sentence intelligibility

Abstract

This study investigated the relative contributions of consonants and vowels to Mandarin sentence intelligibility using a noise replacement paradigm. In Experiment 1, 20 young normal-hearing native Mandarin listeners recognized Mandarin sentences with various amounts of segmental information preserved. Results showed that the vowel-only sentences (consonants replaced by noise) yielded a remarkable 3:1 intelligibility advantage over the consonant-only sentences (vowels replaced by noise). This ratio was larger than that found in English, suggesting that vowels contribute more to sentence intelligibility in Mandarin than in English. Intelligibility increased significantly when a little portion at vowel onsets was added to the consonant-only sentences. However, intelligibility of the vowel-only sentences was still maintained high when the same portion of vowel onsets and an equal amount of vowel offsets were replaced by noise, suggesting that vowel onsets contain redundant information to vowel centers for Mandarin sentence recognition. In Experiment 2, the same listeners discriminated tones of vowels with various durations preserved at either onsets or centers. Results were compared with the findings in Experiment 1, and suggested that lexical tones are relatively redundant for Mandarin sentence intelligibility in quiet.