Remember those old hacker films from the 80-90s? I do. There is especially one that comes to mind and that is “Hackers” from 1995. Jonny Lee Miller from the ongoing Netflix hit Elementary is of the two lead characters. The other one is Angelina Jolie.

If you haven’t seen it, you can here.
In this film, there is a virus released that has an animated Leonardo Da Vinci head speaking out the hackers demands with a distorted voice.

Now, let us play a little bit with a couple of linux commands, espeak and play.
espeak "Hello, you have until next week to run these linux command. Or else.." --stdout | play - tempo 0.8 bend 0.1,-500,0.5 chorus 1 1.5 20 1 3 8 -s echos .7 .7 100 .5 10 0.1 reverb
The first part:
espeak "Hello, you have until next week to run these linux command. Or else.." --stdout
converts a written sentence into audible sound with a synthesized voice. The next part:
play - tempo 0.8 bend 0.1,-500,0.5 chorus 1 1.5 20 1 3 8 -s echos .7 .7 100 .5 10 0.1 reverb
doesn’t do anything useful on its own, but has arguments to distort whatever it will be playing. Actually it will not work as it is. We have to redirect the output from the first part into the second part to make the distortion command arguments be applied to the audible voice. This is done using the pipe key |.
Listen to the result here:
Okay, now we have a audible voice, but how do we save this as file? The play command came from a package called sox and this can be used to save the audible message into a .wav file. We have to reorder a the syntax a little bit, like this:
espeak "Hello, you have until next week to run these linux command. Or else.." --stdout | sox - output.wav tempo 0.8 bend 0.1,-500,0.5 chorus 1 1.5 20 1 3 8 -s echos .7 .7 100 .5 10 0.1 reverb
Then, by using the ffmpeg tool, we can convert the .wav file into a .mp3 file, like this:
$ ffmpeg -i output.wav virus-voice.mp3
Thanks to @climagic for the tip.