We can associate sounds with the different states of a button symbol. Because the sounds are stored with the symbol, they work for all instances of the symbol.
                1. Select the button in the Library panel.
                2. Select Edit from the Panel menu in the upper-right corner of the panel.
                3. In the button’s Timeline, add a layer for sound (Insert > Timeline > Layer).
                4. In the sound layer, create a regular or blank keyframe to correspond with the button state to which 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.
               1. Click the keyframe you created.
                2. Select Window > Properties.
                3. In the Property inspector, select a sound file from the Sound pop-up menu.
                4. Select Event from the Sync 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.