Editing audio is a fairly straightforward process, especially when you have excellent (not to mention free!) tools like Audacity at your disposal. There are a host of different ways to use this program to your advantage; but in this post, we’ll just cover some of the more essential functions that will probably be most useful to you in your training or course development work.
What you will need:
- A supported operating system (Windows XP or later or Mac OS X 10.4 or later)
- Audacity (free download here)
- An audio file (Audacity natively supports major formats like WAV, AIFF, MP3, and OGG. Other formats are also supported with an optional extension; see this page for details)
- Recommended: Headphones or earbuds (you wouldn’t want to distract people around you!)
Zooming in on a Clip
When you first open up an audio file in Audacity (File -> Open), it may look something like this, depending on how long it is:
Good grief! This view may not be so bad if you’re going to be working with large chunks of the clip, but what if you want to make edits to very small selections? To do this effectively, you’ll need to zoom in on the clip. The easiest way to do this is to:
- Hover your cursor over the waveform (the wavy blue part)
- Hold down the Ctrl key on your keyboard
- Then scroll the mouse wheel up at the same time
You can keep doing this until you’ve reached your desired level of detail:
It’s hard to believe that’s actually a fragment of the first waveform, but that’s the magic of the zoom tool. Now you have greater and more precise control over any oddities that may be in your audio file. Note: Scrolling the mouse wheel down will zoom the clip out. If you don’t have a mouse, zooming can still be done with the zoom tool:
After selecting this tool, left-clicking the audio clip will zoom in on it, and right-clicking it will zoom out.
Deleting Unwanted Sound
Did the narrator cough during the recording? You can fix that! start by clicking anywhere on the waveform and dragging it to the left or right to create your selection:
Then, simply hit the Delete key on your keyboard—and just like that, it’s gone. It’s seriously this easy to delete unwanted sound in Audacity.
Silence is golden, and that applies especially to noisy audio clips!
To make a certain part of the clip silent, start by clicking anywhere on the waveform and dragging it to the left or right to create your selection:
To flatline all those waves, just click the Silence Audio button at the top:
And voila! The selection is now totally silent:
But what if you’re trying to insert silence? That’s easy, too. At the top, simply click Generate and then Silence:
You’ll probably want to add seconds of silence, as opposed to samples or some other unit, so make sure you select that option by clicking the small arrow on the right:
Note that the value is separated with a comma:
What’s displayed here is 1 second of silence. If you were to enter 000,010 seconds, it would be 10 seconds; 000,100 seconds would equate to 100 seconds; and so on. When clicking the small arrow to the right, you could also pick one of the hh:mm:ss format (hundredths or milliseconds are recommended) for a layout that might be more familiar to you.
That’s it for now! For further reading, I suggest checking out this list of keyboard shortcuts in Audacity.