Patent Document ID: 8108216
Application ID: 12051104

Base Claim:
1. A speech synthesis system comprising: a dividing unit configured to divide a phoneme string corresponding to target speech into a plurality of segments to generate a first segment sequence; a selecting unit configured to generate a plurality of first speech unit strings corresponding to the first segment sequence by combining a plurality of speech units based on the first segment sequence and select one speech unit string from said plurality of first speech unit strings; and a concatenation unit configured to concatenate a plurality of speech units included in the, selected speech unit string to generate synthetic speech, the selecting unit including a searching unit configured to perform repeatedly, on a computer that includes a processor, a first processing and a second processing, the first processing generating, based on maximum W, wherein W is a predetermined value, second speech unit strings corresponding to a second segment sequence as a partial sequence of the first segment sequence, a plurality of third speech unit strings corresponding to a third segment sequence as a partial sequence obtained by adding a segment to the second segment sequence, and the second processing selecting maximum W third speech unit strings from said plurality of third speech unit strings, a first calculation unit configured to calculate a total cost of each of said plurality of third speech unit strings, a second calculation unit configured to calculate a penalty coefficient corresponding to the total cost for each of said plurality of third speech unit strings based on a restriction concerning quickness of speech unit data acquisition, wherein the penalty coefficient depending on extent in which the restriction is approached, and a third calculation unit configured to calculate a evaluation value of each of said plurality of third speech unit strings by correcting the total cost with the penalty coefficient, wherein the searching unit selects the maximum W third speech unit strings from said plurality of third speech unit strings based on the evaluation value of each of said plurality of third speech unit strings.

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Claim 2:
2. The system according to claim 1 , further comprising: a first storage unit including a plurality of storage mediums with different data acquisition speeds, which store a plurality of speech units, respectively; and a second storage unit configured to store information indicating in which one of said plurality of storage mediums each of the speech units is stored, and wherein the concatenation unit is further configured to acquire the plurality of speech units from the first storage unit in accordance with the information before concatenating the plurality of speech units, and wherein the second calculation unit is configured to calculate the penalty coefficient for each of said plurality of third speech unit strings based on a restriction concerning quickness of data acquisition which is to be satisfied when the speech units included in the first speech unit string are acquired from the first storage unit by the concatenation unit and a statistic determined depending on which one of said plurality of storage mediums each of all speech units included in the third speech unit string is stored in.