Almost all speech is made of bits and pieces of things youíve said before.†††† We have the opportunity to optimize much of our speech as we practice words, tones, and tone combinations.†† Note especially that there are very few tone combinations in Mandarin (64 tri-tones), so itís quite possible to practice all the combinations in a short time, and itís reasonable to assume that they get practiced every day.†† Thus, they could easily be perfected, matching whatever criteria the speaker wishes to optimize.