《诗经》时代，对于双声、叠韵乃至阴阳对转的原理已能运用自如，对于声调的异同也已能感性地认知，汉代民间已有初步的语音分类，东汉学者且已能对音素作感性分析，并自觉运用连读音变同化原理与合音原理作为训诂、注音手段，创制反切所需的语音分析能力，古人早已具备。 In the era of The Book of Songs, the principles of double sound, overlapping rhyme and even the yin and yang transition have been applied freely. The similarities and differences between tones have also been perceived sensibly. There are preliminary phonetic classification of folk in the Han Dynasty. Analysis, and consciously use the theory of simultaneous change and assimilation of the principle of co-tone as a phonetic transcription, phonetic means to create anti-cutting required for voice analysis, the ancients already have.