The arguments wd, wl and wn have to be used isolated, not in conjunction. They basically do the same, ie they set the duration of the zooming window that is slided along the signal. For instance, for a 5 seconds sound with a sampling rate (f) at 44.1 kHz, wl = 4096 is equivalent to wd = 4096 / 44100 = 0.093 s and equivalent to wnb = 5*4096 / 44100 = 53.