If you already open the file menu, then we need to import our sound file, so go to File-Import and select Import to Library, then our job a little easier.
Choose your sound file and click Open.
OK. If you have already done so we can move on, namely we have to go to a movie clip, which is our key, all the animation. Double click on the button.
Now to add the sound so that it is audible during collisions with the mouse on the button we have to go to the second frame on a layer of shares and there, add sound, select a frame like in the image.
If you have already selected a particular frame, drag the audio file from the library onto the Stage in any place. If you do not see the Library panel to use CTRL + L (Mac: cmd + L).
Well, one could say that all this if you want to add sound to the other buttons, it is sufficient to do the same thing with the first button. Go to a movie clip and select the second frame on a layer of shares, drag theaudio file and go!