Unicast of audio books usually means that in a dubbed audio novel, only one person says that all the characters in the novel, including the narration, are completed by one person. This is called unicast. Then double broadcasting means all the roles completed by two people, including the narrator. This is the so-called double broadcast.

With the development of science and technology, especially the development of electronic document recognition technology, you can read e-books after installing reading software. Of course, we can see that there is an audio book on the market, whose target customers are preschool children, who read fairy tales or fables through real person pronunciation or electronic pronunciation, so as to achieve the purpose of early parenting.

Even some products can choose between Chinese and English bilingual reading to improve children's English. An audio book is a work recorded by one or more people with different voice expressions and recording formats according to the manuscript. Common audio book formats include audio tapes, CDs and digital files.