Figure 8: Oscillogram of the speech signal for a realization of the word economic with Hilbert envelope (in orange) outlining the signal is shown on the top panel. The lower panel depicts the discretized MEL scaled spectrum of the signal. The vertical bars are the boundary points that partition the signal into 4 chunks. For one chunk, horizontal lines (in red) highlight one of the frequency bands for which the FBSFs provide summaries of the variation over time in that frequency band. The FBSF for the highlighted band is “band11-start3-median3-min2-max5-end3-part2.”