1. A method of synthesizing speech for a given text comprising: determining a sequence of phonetic components from the given text; determining a sequence of target phonetic elements from the determined sequence of phonetic components; determining a sequence of target event types from the sequence of target phonetic components; establishing a sequence of speech units from a set of stored speech unit candidates, each speech unit being selected using a cost function comprising a unit cost determined with respect to the corresponding target phonetic element, a concatenation cost determined with respect to adjacent speech units, and an event type cost determined with respect to the corresponding target event type.