  Human language, as a typical complex system, its organization and evolution
is an attractive topic for both physical and cultural researchers. In this
paper, we present the first exhaustive analysis of the text organization of
human speech. Two important results are that: (i) the construction and
organization of spoken language can be characterized as Zipf's law and Heaps'
law, as observed in written texts; (ii) word frequency vs. rank distribution
and the growth of distinct words with the increase of text length shows
significant differences between book and speech. In speech word frequency
distribution are more concentrated on higher frequency words, and the emergence
of new words decreases much rapidly when the content length grows. Based on
these observations, a new generalized model is proposed to explain these
complex dynamical behaviors and the differences between speech and book.
