advanced spectrum analysis
Spectrum analysis, FFT computation, is standard fare in
communications theory. When the telephone company [Bell]
researched speech and formats,
they discerned that voice consists principally
of a speech-driver,
and a resonator amplitude-modulating the driver -
with some spectral separation.
By first taking the logarithm of the signal,
the amplitude modulation is separated additively,
though the result tends frequently to cross through
[zero-valued instantaneous amplitudes, in the signal domain]
They called this, the Cepstrum.
The Sceptrum includes differentiation,
which has similar effects of separating the driver and resonator.
Dx f*g x = Df*g + f*Dg
© 1996 GrandAdmiralPetry@Lanthus.net