Mehdi Javadi - Sajad Institute of Higher Education

This paper, embarks upon sound processing techniques in the field of pitch determination which is an important factor in this connection. In this discussion , with representation and introduction of four pitch tracking methods, we have studied and compared them. These methods are: time – domain waveform similarity, auto-correlation , AMDF, and frequency domain harmonics’ peaks determination method. In resume, we, finally , will be introduced to pitch changing methods for vocoders use. For this, we will introduce instrumental pitch shifting and modified formant pitch shifting methods and their speciations.