Usability for Nerds/Hardware/Sound
Humans are used to hearing sounds from everything that we touch and move; and it is natural to use the sound as feedback whenever we use mechanical tools and machines.
Computers and software can generate sounds in order to imitate the sound effects of physical objects. However, these sound effects are often more disturbing than helpful. Have you ever been in a classroom where all the students have their own computer, and all the computers play a jingle when turned on? Then you know what I mean.
Sound effects should be used as little as possible because they can be annoying, especially to other people nearby. Most sound effects should be off by default. There are cases, however, where sound effects are useful, especially when it is necessary to catch the user's attention to some problem or as a confirmation of whether some event has actually occurred, much like tactile feedback from the keyboard.
Sound effects are of course useful in video games. The user may use earphones in order to avoid disturbing other people nearby.