英语时差：蓝鲸是歌唱家？（上）

Did you know that blue whales sing their songs exactly on pitch, with unbelievable accuracy? Scientists at San Francisco State University analyzed over 4,000 blue whale songs off the coast of California. They found that all the whales produced a certain call type at exactly the same pitch — 16.02 Hertz. That’s about four octaves below middle C. Even more remarkable than the fact that all the whales sing certain notes at the same pitch, is how perfectly on pitch they always are. From note to note the whales only vary in pitch by half a percent difference. By comparison, the difference between C and C-sharp is six percent.