12. A speech synthesis system, comprising: a first source of text having content that replies to a user request; a second source of text having content that replies to the user request; a first speech database including pre-recorded speech from a first speaker; a second speech database including pre-recorded speech from a second speaker; a pre-processor to convert text into synthesizable output; a processor to convert first and second text inputs from the first and second sources of text into respective first and second speech outputs corresponding to the pre-recorded speech respectively from the first and second speakers, wherein the content of the first text input and the second text input collectively forms a reply to the user request; a post-processor to adapt the second speech output of the second speaker to sound like the first speech output of the first speaker; an acoustic interface to convert speech output into audio signals; and a speaker to convert the audio signals to audible speech, wherein the speaker outputs the first speech output of the first speaker, and outputs the adapted second speech output of the second speaker wherein the first and second speech outputs include different content and are presented sequentially to a user of the text-to-speech system.
12. A speech synthesis system, comprising: a first source of text having content that replies to a user request; a second source of text having content that replies to the user request; a first speech database including pre-recorded speech from a first speaker; a second speech database including pre-recorded speech from a second speaker; a pre-processor to convert text into synthesizable output; a processor to convert first and second text inputs from the first and second sources of text into respective first and second speech outputs corresponding to the pre-recorded speech respectively from the first and second speakers, wherein the content of the first text input and the second text input collectively forms a reply to the user request; a post-processor to adapt the second speech output of the second speaker to sound like the first speech output of the first speaker; an acoustic interface to convert speech output into audio signals; and a speaker to convert the audio signals to audible speech, wherein the speaker outputs the first speech output of the first speaker, and outputs the adapted second speech output of the second speaker wherein the first and second speech outputs include different content and are presented sequentially to a user of the text-to-speech system. 13. The system of claim 12 , wherein the post-processor modifies models used in conjunction with processing stored speech from the second speaker.