This paper explores the estimation and mapping of probability models of formant parameter vectors for voice conversion. The formant parameter vectors consist of the frequency, bandwidth and intensity of resonance at formants. Formant parameters are derived from the coefficients of a linear prediction (LP) model of speech. The formant distributions are modelled with phonemedependent two-dimensional hidden Markov models with state Gaussian mixture densities. The HMMs are subsequently used for re-estimation of the formant trajectories of speech. Two alternative methods are explored for voice morphing. The first is a non-uniform frequency warping method and the second is based on spectral mapping via rotation of the formant vectors of the source towards those of the target. Both methods transform all formant parameters (Frequency, Bandwidth and Intensity). In addition, the factors that affect the selection of the warping ratios for the mapping function are presented. Experimental evaluation of voice morphing examples is presented.

PURPOSE To investigate quality of life in prostate cancer patients after radical retropubic prostatectomy. MATERIALS AND METHODS 401 men who underwent radical prostatectomy between January 1995 and September 1999 at our clinic were asked for information concerning daily life activities, overall satisfaction, voiding ability and sexual activity in standardized questionnaire. RESULTS The average follow-up was 36 months, 72 % (n = 289) of our patients replied. In 53 (18%) of the men who replied to our questionnaire, the nerve-sparing technique had been used. At the time our patients were questioned, 202 (70%) did not use any pads, and 211 (73%) were satisfied or very satisfied with the outcome. Of these patients 98% would undergo a radical prostatectomy again. 13% (n = 37) of our patients reported limited satisfaction, 14% (n = 41) were not satisfied with their postoperative status. However, 69% of this latter group would nevertheless decide to have a radical prostatectomy again. Of the patients who underwent the nerve-sparing technique, 68% (n = 36) reported sufficient erections for sexual intercourse, four of them under medication with sildenafil. Patients who underwent the nerve-sparing technique reported better results in daily life activities, general health status, IPSS-score and continence. While age at the time of radical prostatectomy did not influence life quality, we found substantial correlation with the postoperative tumor stage. CONCLUSIONS Our results underline the importance of early prostate cancer detection, not only regarding a lower recurrence rate, but also because of a better postoperative quality of life.