Patent ID: 7409347

Claim:
A machine-implemented method comprising: extracting portions from segment boundary region of a plurality of speech segments, each segment boundary region based on a corresponding initial unit boundary; creating feature vectors that represent the portions in a vector space; for each of a plurality of potential unit boundaries within each segment boundary region, determining an average discontinuity based on distances between the feature vectors; and for each segment, selecting the potential unit boundary associated with a minimum average discontinuity as a new unit boundary; wherein the portions include centered pitch periods, the centered pitch periods derived from pitch periods of the segments, wherein the feature vectors incorporate phase information of the portions, wherein creating feature vectors comprises: constructing a matrix W from the portions; and decomposing the matrix W, and wherein the matrix W is a (2(K−1)+1)M×N matrix represented by W=UΣV T where K−1 is the number of centered pitch periods near the potential unit boundary extracted from each segment, N is the maximum number of samples among the centered pitch periods, M is the number of segments, U is the (2(K−1)+1)M×R left singular matrix with row vectors u i (1≦i≦(2(K−1)+1)M), Σ is the R×R diagonal matrix of singular values s 1 ≧s 2 ≧ . . . ≧s R >0, V is the N×R right singular matrix with row vectors v j (1≦j≦N), R<<(2(K−1)+1)M), and T denotes matrix transposition, wherein decomposing the matrix W comprises performing a singular value decomposition of W.