Italians are some of the fastest speakers on the planet, chatting at up to nine syllables (音节) per second. Many Germans, on the other hand, are slow ones, delivering five to six syllables during the same period. Yet in any given minute, Italians and Germans express about the same cover of information.
Scientists started with written texts from 17 languages. They calculated (计算) the information density (密度) of each language in bits. They found that Japanese, which has only 643 syllables, had an information density of about 5 bits per syllable, while English, with its 6949 syllables, had a density of just over 7 bits per syllable. Vietnamese, with its hard system of six tones, topped the charts at 8 bits per syllable.
Next, the researchers spent 3 years recording 10 speakers—five men and five women—from 14 of their 17 languages. Each read aloud 15 identical texts that had been translated into their mother tongue. After noting how long the speakers took to get through their readings, the researchers calculated an average (平均) speech rate per language, measured in syllables/second.
Some languages were clearly faster than others: no surprise there. But when the researchers took their final step to find out how much information moved per second, they were shocked by the agreement of their results. No matter how fast or slow, how simple or hard, each language moved toward an average rate of 39. 15 bits per second.
Language science has explained things so long like grammatical difficulty, so this information passing-on rate has been ignored. But the "why" is another question entirely. Some scientists doubt that the answer has everything to do with the weakness from our biology. Research in neuroscience (神经科学) supports that idea, with one recent paper suggesting an upper number to hearing processing of 9 syllables per second in U.S. English. It really seems that the bottleneck is in putting the ideas together.
