MACROMEDIA FLASH MX 2004-USING FLASH Use Manual page 212

Using the Speech compression option
The Speech compression option exports sounds using a compression specially adapted to speech.
To use speech compression:
In the Sound Properties dialog box, select Speech from the Compression menu.
1.
For Sample Rate, select an option to control sound fidelity and file size. A lower rate decreases
2.
file size but can also degrade sound quality. Select from the following options:
5 kHz
is acceptable for speech.
11 kHz is recommended for speech.
22 kHz is acceptable for most types of music on the web.
44 kHz is the standard CD audio rate. However, because compression is applied, the sound is
not CD quality in the SWF file.
Guidelines for exporting sound in Flash documents
Besides sampling rate and compression, there are several ways to use sound efficiently in a
document and keep file size small:
•
Set the in and out points to prevent silent areas from being stored in the Flash file and to
reduce the size of the sound.
•
Get more out of the same sounds by applying different effects for sounds (such as volume
envelopes, looping, and in/out points) at different keyframes. You can get a number of sound
effects using only one sound file.
•
Loop short sounds for background music.
•
Do not set streaming sound to loop.
•
When exporting audio in embedded video clips, remember that the audio is exported using the
global streaming settings selected in the Publish Settings dialog box.
•
Use stream synchronization to keep the animation synchronized to your sound track when you
preview your animation in the editor. If your computer is not fast enough to draw the
animation frames so that they keep up with your sound track, Flash skips frames.
•
When exporting QuickTime movies, use as many sounds and channels as you want without
worrying about file size. The sounds are combined into a single sound track when you export
as a QuickTime file. The number of sounds you use has no effect on the final file size.
212 Chapter 11: Working with Sound