There are two types of sounds in Flash: event sounds and stream sounds. An event sound must download completely before it begins playing, and it continues playing until explicitly stopped. Stream sounds begin playing as soon as enough data for the first few frames has been downloaded; stream sounds are synchronized to the Timeline for playing on a website.
You can add sounds to scenes and also to buttons to make them more interactive and make sounds fade in and out for a more polished sound track.
You place sound files into Flash by importing them into the library for the current document.
You can import the following sound file formats into Flash:
Flash stores sounds in the library along with bitmaps and symbols. As with graphic symbols, you need only one copy of a sound file to use that sound multiple ways in your document.
Sounds can use considerable amounts of disk space and RAM. However, MP3 sound data is compressed and smaller than WAV or AIFF sound data.
Select File > Import > Import to Library.
To add a sound to a document from the library, you assign the sound to a layer and set options in the Sound controls in the Property inspector. It is recommended that you place each sound on a separate layer.
Select the button in the Library panel.
Select Edit from the options menu in the upper right corner of the panel.
In the button's Timeline, add a layer for sound.
In the sound layer, create a regular or blank keyframe to correspond with the button state to which you want to add a sound.
For example, to add a sound that plays when you click the button, create a keyframe in the frame labeled Down.
Click the keyframe you created.
Select Window > Properties.
In the Property inspector, select a sound file from the Sound pop-up menu.
Select Event from the Synchronization pop-up menu.
To associate a different sound with each of the button's keyframes, create a blank keyframe and add another sound file for each keyframe. You can also use the same sound file and apply a different sound effect for each button keyframe.
To synchronize this sound with an event in the scene, select a beginning keyframe that corresponds to the keyframe of the event in the scene. You can select any of the synchronization options.
Create a keyframe in the sound layer's Timeline at the frame where you want the sound to end.
A representation of the sound file appears in the Timeline.
In the Property inspector, select the same sound from the Sound pop-up menu.
Select Stop from the Synchronization pop-up menu.
When you play the SWF file, the sound stops playing when it reaches the ending keyframe.