1. A method of generating synthesized speech from textual information on a user terminal, said user terminal being provided with a speech synthesis engine having a basic database of speech waveforms, comprising the steps of: starting speech synthesis of said textual information employing said basic database of speech waveforms; sending to a context server a request related to the textual information to be synthesized, the request seeking an incremental database based on a context of said textual information to be synthesized, wherein the context is to be determined from context information extracted from said textual information to be synthesized; receiving the incremental database of speech waveforms associated with said context; managing the composition of an enlarged database of speech waveforms comprising said basic and said incremental databases of speech waveforms; and continuing speech synthesis of said textual information employing said enlarged database of speech waveforms, wherein at least part of the basic database and at least part of the incremental database are used to synthesize the speech.