Creating a Sound Clip with Audacity

1Your own sounds

The Scratch library has hundreds of sounds, but your project becomes truly yours when it uses your own voice, your class clapping a rhythm, or a friend playing the guitar. To record and tidy up such a clip you use an audio editor. Audacity is a free, open-source audio editor. It was started in 1999 by Dominic Mazzoni and Roger Dannenberg at Carnegie Mellon University, first released in 2000, and runs on Windows, macOS and Linux.

2The Audacity screen

• Menu bar at the top: File, Edit, Select, Effect and others.
• Transport buttons: Pause, Play (triangle), Stop (square), Skip to Start, Skip to End, Record (red circle) and Loop.
• Meters: bars that jump up and down to show how loud the microphone and the playback are.
• Timeline: the ruler of seconds above the tracks.
• Track: a strip holding the recording, drawn as a waveform.

3Reading a waveform

Time runs from left to right, and the height of the wave shows how loud the sound is. A flat line is silence. A tall wave is loud. If the wave is squashed flat against the top and bottom edges of the track, the recording was too loud and will sound harsh and crackly; this is called clipping. Move the microphone further away and record again.

4Steps: record, edit, export

1. Check the microphone. Plug it in and make sure Audacity uses it (in Audacity 3, through the Audio Setup button).
2. Record. Click Record (or press R), speak, sing or play, then click Stop.
3. Listen. Click Play or press the Space bar.
4. Select. Drag across the waveform to select a part; it turns a lighter colour.
5. Delete an unwanted part, such as silence or a cough, by selecting it and pressing the Delete key. To keep only the selection and remove everything else, use Trim Audio (Edit menu → Remove Special → Trim Audio, or Ctrl + T).
6. Add effects. Select a part, open the Effect menu and choose one. Newer versions group the effects, so you may find them inside groups such as Fading:
   • Fade In: the sound starts silent and grows to full loudness.
   • Fade Out: the sound shrinks gently to silence at the end.
   • Normalize or Amplify: makes a quiet recording louder.
   • Noise Reduction: lowers a steady background hiss or hum.
7. Undo any mistake with Ctrl + Z.
8. Save the project if you want to keep editing later. Audacity 3 saves projects as .aup3 files, which only Audacity can open.
9. Export a normal sound file that other programs can play: File → Export Audio (Ctrl + Shift + E; in older versions, File → Export), then choose MP3 or WAV, give the file a name and save it.
10. Use it in Scratch: select your sprite, open the Sounds tab, point at Choose a Sound and click Upload Sound, then pick your MP3 or WAV file.

Audacity 4, released in September 2026, has a redesigned screen. If your school has it, the buttons look different, but the same ideas apply: record, select, edit, add effects, export.

5WAV or MP3?

Worked example: Ishimwe's clap clip

Ishimwe records his class clapping a rhythm. The recording is 20 seconds long: 3 seconds of silence at the start, 15 seconds of clapping, and 2 seconds of laughter at the end.

1. He selects the first 3 seconds and presses Delete, then selects the laughter and presses Delete. The clip is now 20 − 3 − 2 = 15 seconds.
2. He selects the first second and applies Fade In, then the last second and applies Fade Out, so the clip does not start or stop suddenly.
3. He exports it as an MP3. At about 1 MB per minute, 15 seconds (a quarter of a minute) is only about 0.25 MB, small enough to upload easily.
4. In Scratch he uploads it to his drum sprite and renames it class claps.

Practice