Sampling rate normalization (8–16 kHz)

Reduce variability between sessions

Stabilize spectral tilt

100–1000 Hz or 50–2000 Hz

Hann or Hamming window, overlapping frames

40–128 bands, Slaney-style normalization

Stabilize dynamic range, remove outliers

Z-score or cepstral mean/variance normalization

Capture short-range dynamics