Time for action – playing audio

We're going to learn how sound effects and music are implemented in Corona to get an idea of how it really works. To play an audio follow the steps:

1. Create a new project folder on your desktop called Playing Audio.
2. In the Chapter 6 Resources folder, copy the ring.wav and song1.mp3 sound files into your project folder and create a new main.lua file. You can download the project files that accompany this book from the Packt Publishing website.
3. Preload the following audio with loadSound() and loadStream():

   ringSound = audio.loadSound( "ring.wav" )
   backgroundSound = audio.loadStream( "song1.mp3" )

4. Play backgroundSound by setting it to channel 1, loop it infinitely, and fade in after 3 seconds:

   mySong = audio.play( backgroundSound, { channel=1, loops=-1, fadein=3000 }  )

5. Add in ringSound and play it once:

   myRingSound = audio.play( ringSound )

6. Save and run the project in the Corona Simulator to hear the results.

What just happened?

For audio that is merely a short sound effect, we used audio.loadSound() to prepare the sound. For audio that is large in size or long in duration, audio.loadStream() is used.

The backgroundSound file is set to channel 1, and fades in at 3 seconds when it starts playing. The loops = -1 statement means that the file loops infinitely from beginning to the end.

Have a go hero – repeating audio with delay

As you can see, loading and playing an audio is really simple. It only takes two lines of code to play a simple sound. Let's see if you can take it up a notch.

Use the ring.wav file and load it through loadSound(). Create a function that plays the audio. Have the sound play at an interval of 2 seconds, repeating five times.