Page  82 ï~~AN OF IMPROVED CEPSTRAL METH SOURCE-FILTER SYSTEMS YN APPLICATION TO MUSIC Thierry GALAS - Xa LAFORIA - UA CNRS N01095 - Labor Universit6 Pierre & Marie Curie - 4, place J Abstract: Most of music sound signals exhi limited number of values only are of import harmonic or inharmonic partials. It is well kno signals leads to difficulties with usual metho deals with a new method for modeling th applications are in view source-filter synthesis, etc such as additive syi o00 Introduction C rmrna P1 ar rmnt a nanwiwta i In mflnly I

Page  83 ï~~The error criterion we choose is the quadrat weighting factor (hl are strictly positive reals): hi (log(si P((i)) i=1 - log(xi))2 This criterion is rather pertinent from a perceptual i Parameter Identification By zeroing the partial derivatives of the erroi ci parameters can be obtained by solving the matrix - A is the p+1 order matrix defined by: n..jajj x hkcos(c.oki) cos(okj) k=1 - C is the vector of the searched parameters. - B is the vector defined by h"1 xhk log(xk/sk) cos(oki) (6) a k ' 1

Page  84 ï~~it is possible compute explicitly the correspon only 3.n su; computational cost of this procedure is of 3.3 Results An example of result is given on Fig 4 to be algorithm to analyse high pitched women voices, with been synthetized with pitch modifications. The high the good adaptation of our new method to the analysis Conclusion We have showed that homomorphic deconvolut those of music sounds with high pitch. We have intro( overcomes the difficulties wich appear with high order of more information or constraints on the spectral ens applied to analysis and synthesis of high pitched sounc