Producing synchronised sound for a computer animated film can be done in a variety of ways:

  • Modify the microfilm recorder to allow a sound track to be drawn in the optical sound area
  • Generate the soundtrack by a synthesiser controlled by a program with the same timing as the one producing the visual image

Merge the audio and sound tracks can be done using existing industry techniques.

Paul Nelson's 1970 UAIDE paper Producing Sound for your Animated Movies showed the film FOCUS and explained the effort needed to add a synchronised sound track.

The Atlas Computer Laboratory had a VCS3 Synthesiser attached to a PDP15 computer and the program that generated the Hash Table Film on the SC4020 also produced the synchronised soundtrack using the VCS3. Additional harmonics were added as the search lengths got longer. Viewers were always amused at this.

Alan Kitching's Antics system was designed to draw a film track that was similar to the VC3 output:

A small section of 'Maxwell's Silver Hammer'

A description is given in the 1975 paper Computer animation with ANTICS.

See also Computer Generated Color Sound Movies (1973), Computer generated optical sound tracks (1972), and Computer Aided Sound Synthesis: CASS Manual (1975).