11. A system for generating a multi-voice font from a plurality of source voice fonts, the system comprising: a phoneme sequencer for parsing input text into a sequence of phonemes; a predictor operable to predict values of voice font characteristics for the phonemes for each source voice font of the plurality of source voice fonts using at least one characteristic model associated with each source voice font; a weight selector operable to assign a duration weight, a f0 weight, and a spectrum weight to each source voice font, the duration weight, the f0 weight, and the spectrum weight determining the relative contribution of the voice font characteristics predicted for the corresponding source voice font to the multi-voice font; an interpolator operable to merge the predicted voice font characteristics with the weights to produce the multi-voice font having voice font characteristics derived from the source voice fonts; and a voice encoder operable to render the input text as computer-generated speech using the multi-voice font, the computer-generated speech having the voice font characteristics derived from the source voice fonts.
13. The system of claim 11 wherein the interpolator further comprises: a duration interpolator operable to merge the predicted duration values for each phoneme with the duration weight for the predicting source voice font to produce an interpolated duration value for each phoneme; a f0 interpolator operable to merge the predicted f0 values for each phoneme with the f0 weight for the predicting source voice font to produce an interpolated f0 value for each frame of the phoneme; a spectral trajectory interpolator operable to merge the predicted spectral trajectory values for each phoneme with the spectrum weight for the predicting source voice font to produce an interpolated spectrum trajectory value for each frame of the phoneme; and a voiced/unvoiced decision interpolator operable to merge the predicted voiced/unvoiced probability values for each phoneme with the spectrum weight for the predicting source voice font to produce an interpolated voiced/unvoiced probability value for each phoneme and compare the interpolated voiced/unvoiced probability value to a threshold to determine an interpolated voiced/unvoiced decision value for each phoneme.