18. A communication terminal capable of text transmission and speech session, wherein a number of the communication terminals are connected to each other through a wireless communication network or a wired communication network, so that a text transmission or speech session can be carried out therebetween, wherein the communication terminal comprises a text transmission synthesizing device, a speech session device and the personalized text-to-speech synthesizing device according to claim 1 .
18. A communication terminal capable of text transmission and speech session, wherein a number of the communication terminals are connected to each other through a wireless communication network or a wired communication network, so that a text transmission or speech session can be carried out therebetween, wherein the communication terminal comprises a text transmission synthesizing device, a speech session device and the personalized text-to-speech synthesizing device according to claim 1 . 19. The communication terminal according to claim 18 , further comprising: a speech feature recognition trigger device, configured to trigger the personalized text-to-speech synthesizing device to perform a personalized speech feature recognition of speech fragment of any or both speakers in a speech session, when the communication terminal is used for the speech session, thereby to create and store a personalized speech feature library associated with the any or both speakers in the speech session; and a text-to-speech trigger synthesis device, configured to enquire whether any personalized speech feature library associated with a subscriber transmitting a text message or a subscriber from whom a text message is received is included in the communication terminal when the communication terminal is used for transmitting or receiving text messages, and trigger the personalized text-to-speech synthesizing device to synthesize the text messages to be transmitted or having been received into a speech fragment when the enquiry result is affirmative, and transmit the speech fragment to the counterpart or display to the local subscriber at the communication terminal.