Method of generating speech from text in a client/server architecture

A terminal comprising:

• a cache memory for storing speech segments received from a server;
• an index list of indices associated with the speech segments, the indices providing access information to respective speech segments;
• and
• means for concatenating the speech segments according to an index sequence received from the server,
• wherein speech segments in the cache memory of the terminal are each associated with a time-to-live value based on how often a respective speech segment is known to be used and speech segments necessary for anticipated subsequent speech to be output are received by the terminal,
• wherein the speech segments, the indices associated with the speech segments and the index sequence are received from the server,
• wherein missing speech segments required for an anticipated standardized speech message to be output are received from the server, the missing speech segments being associated with a longer time-to-live value than speech segments not associated with the anticipated standardized speech message to be output, the anticipated standardized speech message to be output associated with an event of a plurality of events, the event being anticipated based on an application condition, each of the plurality of events associated with a different standardized speech message to be output.

A server for text to speech synthesis comprising:

• means for indexing speech segments;
• and
• means for selecting missing speech segments to be transmitted to a terminal which are necessary to compose a speech message in the terminal together with speech segments already present in the terminal,
• means for transmitting the selected speech segments and indices of speech segments to be output at the terminal;
• means for transmitting an index sequence of speech segments to be put together to form the speech message, the speech segments to be concatenated at the terminal according to the transmitted index sequence;
• wherein the selected speech segments, the indices of speech segments, and the index sequence are transmitted to the terminal, the indices providing access information to respective segments,
• wherein speech segments are each associated with a time-to-live value based on how often a respective speech segment is known to be used,
• means for anticipating an event from a plurality of events based on an application condition, wherein each event is associated with a different standardized speech message to be output;
• and
• wherein missing speech segments required for an anticipated standardized speech message to be output are transmitted to the terminal, the missing speech segments being associated with a longer time-to-live value than speech segments not associated with the anticipated standardized speech message.