中古声母中的全浊音到了《中原音韵》时代全部变读为相应的清音声母。

All voiced obstruents in Mediaeval Times became unvoiced in Era when Zhongyuan Rhymes was written.

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将码字索引空间按照带通浊音度模式进行细致划分，全浊音模式下的基音周期得到了更多的码矢量，从而进一步提高了基音周期的量化精度。

The size of the code book for the pitch is enlarged in the all-voiced mode so that the pitch can be more exactly quantized.

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