The EMS Vocoder 2000 is an analog 16 channel vocoder featuring two mirror image sets of 16 band pass filters with identical center frequency tunings, 16 variable slew rate envelope followers in the Analysis section, and 16 voltage controlled multipliers in the Synthesis section. It also includes an internal oscillator and noise source. Fluctuating Analysis data may be frozen, or held indefinitely to provide unusual effects. The Vocoder 2000 impresses the timbral fluctuations and articulations of an external program signal - eg. a mic/voice - onto the pitch of a selected carrier signal - eg any electronic instrument audio output, making an instrument (synth, drum machine etc) ‘talk’. A wide range of subtle or coarse changes are easily achieved. For instance, the pitch of a voice may be raised or lowered, or a word or sentence may be frozen or slurred. In the case of musical excitation, sources such as organ, guitar, voice or even a recording of an orchestra are filtered at the correct rate and frequencies so as to impose on them the characteristics of the voice input. The robot voices of the Cylons in Battlestar Galactica were created with an EMS 2000 vocoder.