From the silent, suspenseful hum of a predator in the shadows to the piercing shriek of an impending apocalypse, a video game ...

From the Mac startup chime to the dial-up modem handshake, the past few decades have generated some unforgettable sound ...

The line between the two kinds of effect is thin: Foley artists record the sound of a hand twisting a doorknob, but not the sound of the mechanism turning within.

It's that mysterious, creepy, slightly screeching sound effect you've heard so many times before... But how is it made?

That includes a hidden sound effect that only partially plays in the normal course of the game, which you can only hear fully by letting the game run for 14 months straight.

Sound effects aren't preserved with the same care and consistency as images and voices, something the audio archiving community thinks should change.