Sound effects are small audio samples, usually no longer than a few seconds, that are played back on specific game events such as a character jumping or shooting a gun.
Sound effects can be stored in various formats, including MP3, OGG and WAV. Which format you should use, depends on your specific needs, as each format has its own advantages and disadvantages. For example, WAV files are quite large compared to other formats, OGG files don’t work on RoboVM (iOS) nor with Safari (GWT), and MP3 files have issues with seemless looping.
Note: On Android, a Sound instance can not be over 1mb in size (uncompressed raw PCM size, not the file size). If you have a bigger file, use Music instead.
Sound effects are represented by the Sound interface. Loading a sound effect works as follows:
Sound sound = Gdx.audio.newSound(Gdx.files.internal("data/mysound.mp3"));
This loads an audio file called "mysound.mp3" from the internal directory data.
Once we have the sound loaded we can play it back:
sound.play(1.0f);
This will playback the sound effect once, at full volume. The play method on a single Sound instance can be called many times in a row, e.g. for a sequence of shots in a game, and will be overlaid accordingly.
More fine-grained control is available. Every call to Sound.play() returns a long which identifies that sound instance. Using this handle we can modify that specific playback instance:
long id = sound.play(1.0f); // play new sound and keep handle for further manipulation
sound.stop(id); // stops the sound instance immediately
sound.setPitch(id, 2); // increases the pitch to 2x the original pitch
id = sound.play(1.0f); // plays the sound a second time, this is treated as a different instance
sound.setPan(id, -1, 1); // sets the pan of the sound to the left side at full volume
sound.setLooping(id, true); // keeps the sound looping
sound.stop(id); // stops the looping sound
note: These modifier methods have limited functionality in the JavaScript/WebGL back-end for now. As of 1.9.6 setPan() is only working when flash is supported and enabled GwtApplicationConfiguration.preferFlash = true
note: setPan() method does not work with stereo sounds
Once you no longer need a Sound, make sure you dispose of it:
sound.dispose();
Accessing the sound after you disposed of it will result in undefined errors.
Multiple sounds cause freezes on Android
As stated on an Audio topic the Android has many issues with audio in general. One of them, is that waiting for sound ID might take quite a lot time. The sounds in Libgdx are playing synchronously by default. It causes main loop to be frozen for significant time if you play a lot of sounds at once. Especially this issue noticeable on Android 10.
The solution is to make them playing asynchronously. However it will cause inability to use sounds methods where ID is required. More info provided here - Audio#audio-on-android