Also affected. I can reproduce this perhaps near 50% of the time by opening a terminal and running:
aplay /usr/share/sounds/alsa/Front_Left.wav
And immediately on pressing enter turning the screen off.
You should do this somewhere reasonably quiet and you will hear the crackle/static/hissing sound a few seconds after the sound finishes.
Also affected. I can reproduce this perhaps near 50% of the time by opening a terminal and running: sounds/ alsa/Front_ Left.wav
aplay /usr/share/
And immediately on pressing enter turning the screen off.
You should do this somewhere reasonably quiet and you will hear the crackle/ static/ hissing sound a few seconds after the sound finishes.