How to Loop Audio in Audacity

Create Looping Sound Effects for Games (for free) with Audacity

In Articles by John2 Comments

In this article I’m going to show you how to turn ambient sounds, like engine recordings, background noise or environment audio clips, into seamlessly looping sound effects that you can use in your game.

What’s more, I’ll be doing it in Audacity which, apart from being pretty darn good, is completely free.

How to make looping sound effects with Audacity

To demonstrate how to make a loop from a longer audio clip, I’m going to create a looping wind sound effect from a simple recording of me blowing into my microphone (with a pop shield).

Here’s what the original recording sounds like:

I’m going to show you how to cut out a section of the recording and use it to create a short, seamless loop.

Here’s how to do it…

  1. Download and open Audacity, if you haven’t already.
  2. Drag and drop your source audio into the project window. You’ll be asked if you want to make a copy of the file, you can choose either option but it’s usually better to select ‘Make a Copy’.
  3. Select the section of audio that you’d like to loop using the Select tool Audacity Select Tool Icon.

Select Audio Section to loop in Audacity

  1. Use Trim Outside Selection Audacity Trim Outside Selection Icon to remove audio either side of the selection.

Cut a section of an audio clip in Audacity using the trim tool

  1. Switch to the Time Shift tool  and move the trimmed audio to the start of the track.

Creating a crossfade in Audacity

  1. Switch back to the Select tool Audacity Select Tool Icon and select a section from the start of the clip. How much of the clip you select will affect how long the crossfade is during the loop so make sure to select enough for a smooth fade (aim for at least a few seconds).

Select a crossfade section in Audacity

  1. Use the Cut tool Audacity Cut Tool Icon to cut the selection, click off of the current track (in the space below) and use the Paste tool Audacity Paste Tool Icon to paste the cut section on to a new track.
  2. Using the Time Shift Tool Audacity Time Shift Tool Icon , move the newly pasted section to the end so that it just overlaps the end of the original audio track.

Using Audacity Time Shift Tool to create Crossfades

  1. Using the Select tool Audacity Select Tool Icon , click and drag to highlight a crossfade region across both audio tracks, using the yellow guide lines to snap to the end of the top clip and the start of the bottom clip.

How to select a crossfade region in Audacity

  1. Select Effects > Crossfade Tracks from the menu.

Audacity Crossfade Tracks Effect Menu

  1. For the Fade Type choose Constant Power 1 and hit OK. This prevents a dip in volume in the middle of the crossfade that you might get with a linear fade curve.

Choose Constant Power 1 for equal power crossfades in Audacity

  1. Your audio tracks should now look something like this:

Equal power crossfades in Audacity example

Creating the seamless loop

  1. You’re almost done! Zoom in to the very beginning of the first audio clip, make sure you’re at the start and that you’re zoomed in so much that the audio wave becomes a single line, instead of a block of colour.
  2. Using the Select tool Audacity Select Tool Icon Select a, very, small section at the beginning of the audio wave. Select Effects > Fade In to apply a short fade in.

Select audio wave section Audacity

  1. Zoom to the very end of the second clip and do the same, this time selecting Effects > Fade Out.

Fade out Effect Audacity

  1. Select both clips using Select > All or by pressing cmd+A / ctrl+A. Preview the loop by selecting Transport > Playing > Loop Play. If everything is sounding right, it’s time to export.

Play a loop section in Audacity

Adding a short fade in and out prevents the audio file from popping when it first plays from silent. It works best when you try to match the natural curve of the audio wave. If you can hear a quick, smooth dip, like a bump at the loop point, then the fades are too long, if you can hear a noise that resembles a static pop, the fades are too short. You may need to listen with headphones to check this.

  1. Change the sample rate. If, like me, you’ve been using a high sample rate audio clip (my file was 96khz) then now would be a good time to choose a lower sample rate for export. Select Project Rate in the bottom left corner and choose a new sample rate. For game development, and many other uses such as CD quality music, 44100 (44.1khz) is more than adequate. 48000 (48khz) is also fine, but is more often used in video work.

Select Sample Rate in Audacity

  1. And you’re done! Select File > Export and choose 16bit WAV to save the loop. Please note that many compressed formats, particularly MP3 do not loop properly so you’re better off using uncompressed audio.

The End Result

Here’s the final loop, repeating three times:

Now it’s your turn

Audacity makes it easy to professionally edit and create looping sound effects without spending money on pro audio software that you probably don’t need for basic tasks like this.

Now that you can edit your own looping sound effects, what will you make and what will you use it for? Let me know by leaving a comment before you go.

Image Attribution

Icon made by DinosoftLabs from www.flaticon.com is licensed by CC 3.0 BY
Audacity logo Copyright © 2019 by Audacity

Comments

  1. Avatar

    thank you for the guide ,i will use it for games and music 🙂

  2. Avatar

    This is the second guide of yours that I have used. Thank you for making your expertise available to new developers.

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