13. The system of claim 11 , further comprising: receiving a text input corresponding to an utterance during a massive synthesis phase associated with the concatenative speech synthesis.
11. A system configured to perform concatenative speech synthesis comprising: one or more processors configured to access a plurality of speech synthesis units from a speech database and determine a similarity between the plurality of speech synthesis units, wherein determining the similarity is based upon, at least in part, a similarity factor, the one or more processors further configured to retrieve two or more speech synthesis units having the similarity, the one or more processors further configured to prune at least one of the two or more speech synthesis units based upon, at least in part, the similarity, wherein pruning is based upon, at least in part, a delta unit appearance frequency “DUAF” technique and wherein the DUAF is based upon, at least in part, a change in a unit appearance frequency and a change of the similarity factor.