Add to ORKGThesis is dedicated to the making of a system for voice conversion. To methods, which alter voice of one person in a way, that it could be possible for listener to mislead it for someone elses voice. In the first part, Harmonic plus Noise Model (HNM) is described. Signal analysis and synthesis are its main purposes. Methods of voice conversion are considered in the second part. Prosodic modifications are introduced at first and then modification of a spectral envelope is discussed (Especially aplication of conversion matrices). Dynamic Time Warping (DTW) and Linear Prediction Coding (LPC) methods are explained briefly. In last section, implementation process is described and achived results are discussed. Ways of further development are sug...