DIRECT MEL-SCALE FREQUENCY WARPING

• We can warp the linear frequency axis directly. Let denote the center frequencies on the mel scale. We can warp these frequencies using a simple linear transformation:
• We can also warp the discrete Fourier transform samples directly using a similar linear compression.
  
  
• A typical range for the warping factors is [0.8, 1.2].
  
  
• What are the relative merits of this approach?