Like the infinite monkeys typing Shakespeare, but with audio instead.
If there was a program that created a series of sounds at random intervals, pitches, amplitudes, etc., how long would it take to produce an output that sounds like music, some sort of recognisable recording (e.g. a bell ring, a dog barking), or perhaps even a human voice?
It’s also impossible to answer because pareidolia will cause different people to hear what they think is music or speech in random noise at different thresholds, dependent on the person.