1. A personalized text-to-speech synthesizing device, comprising: a processor; a memory; a personalized speech feature library creator, configured to recognize personalized speech features of a specific speaker by recognizing whether a keyword from preset keywords associated with the specific speaker occurs in a random speech fragment of the specific speaker that includes multiple words including the keyword and speech in addition to the keyword, the random speech fragment being part of a multiple speaker conversation including the speaker, and, if the keyword is found in the random speech fragment, recognizing the personalized speech features of the specific speaker based on a comparison of a standard speech of the keyword and the speech of the keyword by the specific speaker in the random speech fragment, thereby to create a personalized speech feature library associated with the specific speaker, and store the personalized speech feature library in association with the specific speaker; and a text-to-speech synthesizer, configured to perform a speech synthesis of a text message from the specific speaker, based on the personalized speech feature library associated with the specific speaker and created by the personalized speech feature library creator, thereby to generate and output a speech fragment having pronunciation characteristics of the specific speaker.