Scaling laws in human speech, decreasing emergence of new words and a generalized model

TL;DR

This paper analyzes the organization of human speech, revealing that speech and written texts follow Zipf's and Heaps' laws but differ in word distribution and growth, leading to a new generalized model of language dynamics.

Contribution

It provides the first comprehensive analysis of speech organization, highlighting differences from written texts and proposing a novel model to explain these linguistic dynamics.

Findings

Speech follows Zipf's and Heaps' laws like written texts.

Word distribution in speech is more concentrated on high-frequency words.

Emergence of new words decreases rapidly with increasing speech length.

Abstract

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.