svoid trainVAD() {
  BWImage img1 = frequencyImage(voiceMegaMix());
  BWImage img2 = frequencyImage(nonVoiceMegaMix());
  int clipLength = iround(2.0*spectro_pixelsPerSecond());
  int stepSize = clipLength/4;
  print(+clipLength);
  for (IntRange r : stepIntRange(clipLength, intRange(0, img1.getWidth()), stepSize))
    print(r);
}