Sound

Sound, as pointed out in Chapter 3, is both over- and underused in interaction design. Nearly everyone has had the experience of going to a Web site only to have it suddenly blast music, sending you scrambling to turn the thing off. But sound, done well, can subtly enhance an interface.

Sounds can be ambient cues that something has happened so that users don't have to constantly visually monitor the application for changes. This use of sound is especially helpful in applications with frequent changes that may occur while the user is otherwise occupied. A ding! indicates that an e-mail has arrived. The door-opening sound indicates that a buddy has signed onto the instant messenger client. The ring of a mobile phone indicates that a text message has arrived. These are all helpful sound cues.

How can you tell if a sound will, over time, become an annoyance? Record it. Test it on others and see what they think. Listen to it frequently. Use the application yourself and see if you become annoyed at it. If you do, probably others will as well.