Improved speech modification method

A speech modification method presented by Griffin and Lim [1] involves modifying the Short-Time Fourier Transform Magnitude function of the original speech, and using it as a reference to iteratively approximate a modified waveform. This method has been successfully applied to time-scale modification and noise reduction of speech [1-3]. In this paper, we discuss our experiments in applying the algorithm to the independent modification of formant and pitch information.