Audacity: The Free Dimensional Sound Editor, Part Two

Continuing from last week’s introduction to Audacity, this week you’ll take a deeper dive into some of Audacity’s advanced editing features by learning how to create a professional sounding introduction for your audio projects. These are the exact techniques I used to create the introduction music and voice-over for the Frugal Tech Show podcasts.

This article focuses on Audacity 1.3.12 Beta on Ubuntu Linux 10.10 and uses a Logitech 350 USB Headset with built-in microphone. I selected two audio files for this project: A 30 second music clip and an 11 second voice-over clip. Mixed together with a little advanced Audacity magic creates a studio-quality introduction that costs nothing and only takes about 30 minutes to perform.

The Setup

To mix two files together into a single usable sound byte, either you have to record multiple tracks into Audacity directly or to open pre-existing files and work with them. We’ll be working with the latter scenario for this demonstration.

To create a single file that mixes voice and music, open Audacity, select File->Open, search for your file, select the file, click the Open button and the sound file is read into the Audacity editor. Add the second file into the editor by selecting File->Import->Audio, search for your file, select the file, and click the Open button.

Both files are now in the editor. See Figure 1. The upper track is the sound file, the lower is the voice-over file. Although, the order of the files in the editor doesn’t matter. Note that both files load at position 0 in the editor window.

Figure 1: Music Track and Voice-over Track Loaded into Audacity

Insert Silence

To create the intro music to voice over transition, add silence to the voice-over track. Since we want to play intro music, then add the voice-over, then finish off with a second or two music, add 16 seconds of silence.

Click your mouse into a silent region, if one exists, or at the beginning of the voice-over track, select Generate->Silence, enter 16 (seconds) into the Silence Generator dialog that appears. See Figure 2.

Figure 2: Audacity’s Silence Generator

Figure 3 shows the result of the 16 second silence insertion.

Figure 3: Sixteen Seconds of Silence Added to Voice-over Track

You might find that your tracks are linked and when you insert silence into the voice-over, both tracks move 16 seconds to the right, which is not the desired results. See Figure 4 for an illustration of this.

Figure 4: Sixteen Seconds of Silence Added to Linked Voice-over Track

Note the “Chain-link” symbol in the upper track and that 16 seconds of silence was inserted into both tracks. To remove this anomaly, select Edit->Undo Silence. To unlink the two tracks, select the Link Tracks icon to unlink the two tracks as shown in Figure 5.

Figure 5: Unlinking Linked Tracks

Finishing Touches