26. A personalized speech feature extraction device, comprising: a processor; a memory; a keyword setting unit, configured to set one or more keywords suitable for reflecting the pronunciation characteristics of a specific speaker with respect to a specific language, and store the keywords in association with the specific speaker; a speech feature recognition unit, configured to recognize whether any keyword 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 obtained from a multiple speaker conversation including the speaker, and when a keyword associated with the specific speaker is found in the speech fragment of the specific speaker, recognize speech features of the specific speaker according to a standard pronunciation of the recognized keyword and the pronunciation of the speaker; a speech feature filtration unit, configured to filter out abnormal speech features from the keyword as found in the speech fragment through statistical analysis while retaining speech features reflecting the normal pronunciation characteristics of the specific speaker, when the speech features of the specific speaker recognized by the speech feature recognition unit reach a predetermined number, 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 stored personalized speech feature library associated with the specific speaker.
26. A personalized speech feature extraction device, comprising: a processor; a memory; a keyword setting unit, configured to set one or more keywords suitable for reflecting the pronunciation characteristics of a specific speaker with respect to a specific language, and store the keywords in association with the specific speaker; a speech feature recognition unit, configured to recognize whether any keyword 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 obtained from a multiple speaker conversation including the speaker, and when a keyword associated with the specific speaker is found in the speech fragment of the specific speaker, recognize speech features of the specific speaker according to a standard pronunciation of the recognized keyword and the pronunciation of the speaker; a speech feature filtration unit, configured to filter out abnormal speech features from the keyword as found in the speech fragment through statistical analysis while retaining speech features reflecting the normal pronunciation characteristics of the specific speaker, when the speech features of the specific speaker recognized by the speech feature recognition unit reach a predetermined number, 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 stored personalized speech feature library associated with the specific speaker. 28. The personalized speech feature extraction device according to claim 26 , wherein the speech feature recognition unit is further configured to recognize whether the keyword occurs in the speech fragment of the specific speaker by comparing the speech fragment of the specific speaker with the standard pronunciation of the keyword in terms of their respective speech spectrums, which are derived by performing a time-domain to frequency-domain transform to the respective speech data in time domain.