Playing Sounds in ActionScript 3 by
kirupa | 24 March 2010
Playing sounds in ActionScript is fairly straightforward
thanks to the Sound class. All you really need to do is put
the class to good use to that you can load a sound,
buffer/preload it, and then play it. In this short article, I
will provide you with the code you need and explain how
Note - This tutorial covers how to play sounds using
ActionScript 3. For playing sounds using ActionScript 1,
Overview of Playing Sound
In general, when it comes to playing sound in code, there
are several things that you need to do:
Access an External MP3 File
The sound files that you load will not be included
inside the SWF file. The files need to be located
externally such as alongside your SWF file.
Preload the Sound
Before playing the sound, you need to make sure the
sound has been fully loaded first. If you didn't do
this, your sound will stutter on slower connections.
Streaming sounds will be covered in a future article, so
Play the Sound Once
your sound has been fully loaded, all that is left is
for you to actually play it.
Now that you know, at a very high level, what it takes to
play a sound file, lets' go ahead and look at the code.
The Code The code for
pointing an external sound file, preloading it, and playing
it can be written in the following lines of code:
to sound file>"));
The first line is pretty straightforward. I am declaring
a variable called soundClip whose type is Sound. Another way
of saying it is that I have a Sound object called soundClip.
You can learn more about classes / types / objects in my
Classes in ActionScript 3 article.
Next up is the init() function:
to sound file>"));
This function gets called first when you run your
application because it gets called - the function call is
directly below the function!
The code inside the init
function points to the sound file you want to load and sets
up the event handlers for letting your app know when the
sound has been fully downloaded. Let's look inside it to
The first line of our init method initializes our
soundClip object to a new Sound object:
While before you simply declared a variable called
soundClip whose type is Sound, it isn't until you initialize
it that the Sound object is actually created. With this
object created, you have access to all of the properties the
Sound class provides you with.
The first property we will look at is
to sound file>"));
The load property takes the URL of the sound file to
load. The moment this line gets executed, your sound file
begins its download. It is important that you are aware of
the sound file downloading and when it finishes downloading.
The next two lines help you with just that:
Both of these lines set up listeners from our Sound
object that associate an event with a function to call when
that event is fired. The function that reacts to an event is
often called an event handler.
In the first line, we listen to the Complete event and
play the soundLoaded function when the sound file's
download has fully completed.
In the second line, we do something similar except we
play the soundLoading function as the sound file is
// preloader information
The last line we looked at was one that called a function
as your sound file was downloading. That function is called
soundLoading. With each chunk of data that gets downloaded,
this function gets called. Notice that it takes an argument,
and that argument is of type ProgressEvent.
The ProgressEvent class contains properties that you can
use to gauge the progress of the download. The two
properties that would be relevant are
bytesTotal. You can use
them both to get the current progress by dividing the values
Here is an example of me using the ProgressEvent object e
and dividing the number of bytes loaded by the total size of
The final thing to look at is our soundLoaded function:
This function is the event handler for the Complete event
that fires when the sound file you are loading has fully
downloaded. With our sound fully loaded, the only thing that
remains is to actually play your sound. That is done by
calling the play() method
on your soundClip object of type Sound.
Conclusion That's all there is to loading
sound in ActionScript. As long as you use the Sound class
and play the sound only after it has fully loaded,
everything is golden....like a retriever!
If you have questions, need some assistance on this topic, or just want to
chat - post in the comments below or drop by our friendly forums
(where you have a lot more formatting options)
and post your question. There are a lot of knowledgeable and witty people who
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Please feel free to contact me directly at kirupa[at]kirupa.com.