1. A method for providing speech parameters to be used for synthesis of a speech utterance, comprising: receiving an input time series of first speech parameter vectors {x i } 1. .. m allocated to synchronisation points 1 to m indexed by i, wherein each synchronisation point is defining a point in time or a time interval of the speech utterance and each first speech parameter vector x i consists of a number of n 1 static speech parameters of a time interval of the speech utterance, preparing at least one input time series of second speech parameter vectors {Δ i } 1. .. m allocated to the synchronisation points 1 to m, wherein each second speech parameter vector Δ i consists of a number of n 2 dynamic speech parameters of a time interval of the speech utterance, extracting from the input time series of first and second speech parameter vectors {x i } 1. .. m and {Δ i } 1. .. m partial time series of first speech parameter vectors {x i } p. .. q and corresponding partial time series of second speech parameter vectors {Δ i } p. .. q wherein p is the index of the first and q is the index of the last extracted speech parameter vector, converting the corresponding partial time series of first and second speech parameter vectors {x i } p. .. q and {Δ i } p. .. q into partial time series of third speech parameter vectors {y i } p. .. q , wherein the partial time series of third speech parameter vectors {y i } p. .. q minimises differences to the partial time series of first speech parameter vectors {x i } p. .. q , the dynamic characteristics of {y i } p. .. q minimise differences to the partial time series of second speech parameter vectors {Δ i } p. .. q , and the conversion is done independently for each partial time series of third speech parameter vectors {y i } p. .. q and can be started as soon as the vectors p to q of the input time series of the first speech parameter vectors {x i } 1. .. m have been received and corresponding vectors p to q of second speech parameter vectors {Δ i } 1. .. m have been prepared, and combining the speech parameter vectors of the partial time series of third speech parameter vectors {y i } p. .. q to form a time series of output speech parameter vectors {ŷ i } 1. .. m allocated to the synchronisation points, wherein the time series of output speech parameter vectors {ŷ i } 1. .. m is provided to be used for synthesis of the speech utterance.