Non-negative temporal decomposition of speech parameters

We present a non-negative temporal decomposition method for line spectrum pair and articulatory parameters. Based on the multiplicative update rules derived from a non-negative matrix factorization algorithm, these parameters decompose into a set of temporally overlapped event functions that are restricted to the range and corresponding event vectors. With the proposed method, the RMS error of the measured and estimated articulatory parameters is 0.16 mm and the spectral distance of the measured and estimated line spectrum pair parameters is 1.97 dB. These results also show that these estimation errors of proposed method are significantly smaller than those of the conventional method. This technique will be useful for many applications, such as speech coding and speech modification.