As you develop a game, there are three senses you can use to involve a game player: touch, sight, and sound. Until computers start emitting odors and flavors, those are all we have to work with. The visuals (sight) and the control (touch) of a game tend to get a lot of attention during game design and development. In this chapter we focus our attention on the odd sense out, hearing. Sounds used in a game can be any of the following:
Songs Full-length musical compositions created or licensed for your game. Songs can play in the background during the game or be triggered to play after something happens (for example, winning the game).
Music loops Short pieces of music that play repeatedly. A music loop can range from about 1 second to several seconds, and have a file size that is a fraction of that of a full song.
Sound effects Sounds triggered by the result of an action, or synchronized with a visual event.
Voice Spoken-language clips recorded or licensed for your game. Voice can be used in animations before a game, throughout the game to show characters talking, or as a sound effect (for example, a person yelling "Ouch!" when struck by a sword).
Music and voice are not always necessary in your games, but sound effects definitely are. Here are the top three reasons why you should not neglect sound in your games:
Sometimes, if you play your cards right (so to speak), sounds can achieve two or more of these goals at the same time. For example, let's say you're playing a game in which you must solve a puzzle somewhere in a house. When you do, you get to open a locked door to another room, and a short, cheerful tune is played. The sound conveys the information that "hey, you did something right!" as well as helps to create or elicit an emotional response of satisfaction or excitement.
After playing a good game, I rarely find myself thinking, "Wow, the sounds in this game are great!" This isn't because of bad sound; if the sounds are doing their job, then they will most likely not stand out. It's often the same in movies. There are many scenes in which the frantic music enhances the suspense or action. You probably don't notice how much of an effect the sound has. If someone doesn't really notice the sound in your game, then the sound is most likely doing its job properly. More often than not, sounds that stand out are sounds that do not belong.
In the rest of this chapter we will talk about how to use and create sound effects and loops, and how to use ActionScript with sound files to create effects.