As [mitxela] explains, this can be done with an MP3 file of white noise, and that is a solution that works perfectly well for most practical purposes. However he found himself wanting a more ...

Making sound with digital logic ... a transistor buffer circuit, we’d lose the roughly 0.6 volts needed for the base-emitter bias voltage. And heck, this is Logic Noise. So break out the 4069UB ...