Compressing Sound
When publishing a Flash Movie (SWF) with sound embedded in it, Flash will compress the sound for better file size and try to retain the highest quality possible in the process. You can compress all the sounds in your file at once from the Flash tab in the Publish Settings, as shown in Figure 6.7. You can adjust both Event and Stream sounds by clicking their associated Set button.
Figure 6.7. In the Flash tab of the Publish Settings, you can control overall sound compression of your Flash file.

- Default
This choice will use the Publish Settings of the file. - ADPCM (Advanced Differential Pulse Code Modulation)
This compression is here for one reason only: to be used in the Flash 3 or older players. This option has become obsolete because with the Flash 4 player or later, you can use MP3 compression. However, if you are creating content for older players, you may want to try this one out. - MP3
This choice produces sounds of good quality and good compression and can be used in the Flash 4 player or later. - Raw
This is a great setting for CD media because of the high quality of the sound. But because it uses no compression, the size of your movie will increase a great deal as well. - Speech
This is a great choice for audio narration of your Flash file. Because this choice is designed for straight speech audio, it can often produce a better quality of compression and sound for narrations than MP3 compression.
Figure 6.8. The Sound Settings dialog box.

- AIFF
Similar to the WAV file, but created on Macs. Many Windows machines may have problems with these files. - MP3
One of the most popular, and therefore readily available, sound file formats on the web. Excelling in both sound quality and small file size, MP3s work well within Flash. This format is also the only sound format that can be loaded into the Flash movie (SWF) at runtime. - WAV
WAV files, although larger than MP3s in file size, still maintain good sound quality and are a Windows sound format standard.
You have seen how to work with audio manually on the stage, but in the next section you learn how to work with sound in ActionScript.