There is a fascinating piece of history regarding the creation of the THX Deep Note sound. Essentially the folks as the Lucasfilm Computer Division created it using an Audio Signal Processor (in the days before DSP chips) by writing 20,000 lines of C which generated a “sequence of parameters that drives the oscillators on the ASP. That 20,000 lines of code produce about 250,000 lines of statements of the form “set frequency of oscillator X to Y Hertz””.
That would make the deep note one of the earlier examples of computer generated sound.