rlr (12/22/82)
Sounds a lot like an ordinary vocoder (NOT vocoRder) to me.
A vocoder is a device (invented, by the way, at Bell Labs circa 1935) which
imposes the audio spectrum of one sound onto another sound. What it does
is to 1) analyze the spectrum of a sound (usually human speech) and 2) use this
derived spectrum (really the set of amplitudes measured at a broad band of
frequency ranges) to control the level of a series of bandpass filters
through which a second sound is passed. (You can think of these bandpass
filters as a sophisticated version of an audio equalizer with a large number
of sliders, where the position of the sliders changes over time based on
the audio spectra of a person's speech.)
Simply put, it imposes the characteristics of one sound onto another, and can
thus make virtually any sound with a broad enough spectrum and long enough
duration sound like someone speaking. It is an extremely common musical/audio
device, used by groups like Kraftwerk and (in a more SF-related vein) by
the people who brought you Cattlecar Fascistica. The "voice" of the Cylon
warriors ("By your command") was generated by imposing a human voice onto a
sustained buzzer-like sound that does not waver in pitch or volume. This
technique should not be confused with genuine computer speech synthesis,
although it is often used to pass for the real thing (esp. in movies/TV).
There is nothing unusual about Lucasfilm having such a device.