Formant Extraction from Phase Using Weighted Group Delay Function

A method to extract formants from Fourier transform (FT) phase using a group delay (GD) function is presented. The GD function of the speech signal is difficult to process owing to the presence of large amplitude spikes. The spikes are de-emphasised by modifying the expression for computing the GD function, which facilitates formant extraction. © 1989, The Institution of Electrical Engineers. All rights reserved.