Speech Prosody 2004
Tonal languages, such as Mandarin, convey information using both phonemes and tones. Using a recently proposed framework for measuring the functional load of a phonological contrast (i.e. how much use a language makes of the contrast), we carry out several computations to estimate how much use Mandarin makes of tones. The most interesting result is that identifying the tone of a syllable is at least as important as identifying the vowels in the syllable. Another computation suggests that the contrast between low and neutral tone carries relatively little information.
Bibliographic reference. Surendran, Dinoj / Levow, Gina-Anne (2004): "The functional load of tone in Mandarin is as high as that of vowels", In SP-2004, 99-102.