Getting Started with Sound Editing
Audacity is free sound-editing software that allows you to cut up audio tracks, modify them, combine them, and record your own sound. Today we'll use it to import a track, modify it, cut it into pieces, and layer a voice on top of music.
Download a track
Much the way we did last week, we'll start by downloading a track from the Free Music Archive. Click around until you find a piece of music that you like. Download it by clicking on the "down" arrow. Remember where you saved the file so you can locate it later.
Locate Audacity and open it by double-clicking on the icon. When Audacity opens, it automatically creates a new project. Go ahead and click on File and then Save as... to save your project now, just in case your computer crashes. Give it a title and save the project somewhere you can find it again later.
Import your track
To get the music you downloaded into Audacity, click on File, then Import, and then Audio... Locate the file you downloaded in the first step and select it. (Or you can drag and drop the file into the Audacity window.)
Play your track
To listen to your track from within Audacity, click on the green Play button. You can start at a certain point or play only a selection by clicking, or clicking and dragging, the playhead (the vertical line that appears over the waveforms). And, of course, you can stop it by clicking the black Stop button.
My Audacity window shows two waveforms layered one on top of the other because my track is in stereo. Each waveform is a "channel."
Cut out part of your track
You may find that you'd like to remove a cough or a long pause from a track. We'll practice cutting out part of our audio. To do that, select a portion of your audio track by clicking and dragging the playhead. Then click on Edit and then Cut. Audacity will cut out that portion of the track and shift the audio over, so there isn't a gap.
Paste the "cut" portion elsewhere
You can even drop the selection you've excised elsewhere in the track. Click the playhead somewhere along the waveform and select Edit and then Paste. Audacity will drop that sample in.
Zoom in to a portion of the track
Sometimes it's easier to work with a track if you zoom in on the waveform. To do that, use the button picturing a magnifying glass with a plus sign on it. (Then, of course, you can zoom out with the other magnifying glass button.)
Fade in or out
Click and drag the playhead to select a portion of your track. Then, from the Effects menu, select Fade in or Fade out. The audio will get louder or softer during the interval you've selected. If you want, you can play with the other effects, too. (Create an echo! Create distortion!)
Get spoken sound to layer over your music
For your video project, you may want to record your own voiceover. But today, let's practice layering a voice over music by grabbing some poetry. In your browser, go to the Penn Sound archive of poetry readings at http://writing.upenn.edu/pennsound/singles/. You can listen to individual pieces by clicking on the blue arrow. (Try to find something relatively short.) When you've found something you like, click on Download and then, from the next window, click on the down arrow.
Import your new track into your Audacity project
You can just drag and drop your new file into the Audacity project window. Now your new track will appear beneath the music you started with. Check to see how it sounds by pressing the Play button.
Change the relative volume of your two tracks (1)
When I imported my poetry reading, it was way too soft compared with my music. Let's make the music softer. We can do that by clicking on the Envelope button. ("Envelope" refers to the "volume envelope," or overall sound of the track.) Once you click that button, the volume envelope becomes visible as a blue line at the bottom and top of the waveform.
Change the relative volume of your two tracks (2)
Now, with the envelope tool selected, drag the volume envelope of your music track in toward the middle to make the sound softer. Notice that each time you click, you create a control point -- a little handle with which you can manipulate the sound. This allows you to make the track louder and softer as your prefer. You can fade out the music to highlight the voice, for example.
Change the placement of the voice track
Perhaps you want the voice to show up a little later along in the music track. You can do that by clicking on the time shift button. (It looks like a line with an arrow at either end.) With that button selected, you can click and drag individual tracks.
Export your file
Now that you've created a work of musical genius, export the whole thing as a sound file. Click on File, then **Export **and export your file as a WAV. Imovie can import and play WAV files.
(A note on this: You can also export your file as a more familiar mp3 file, but you need to download something called a LAME library in order to do this. Audacity will provide instructions on how to do this if you attempt to export your file as an mp3.)
More Audacity help
Audacity tutorials by librarians (the most helpful people around; search for "Audacity")