Sound Design Tricks for Audacity

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When you’re new to voice over production and sound design, there are a few tips that will get you up to speed fast and prevent mistakes. We’ll concentrate on how to do this in Audacity (download here), but these tips are useful for any digital audio editing software, system or workflow. (This assumes you have some familiarity with the basics of Audacity and your computer. For just the basics of Audacity, start here.)

1. Save the Project, Not Just the Export

Making a commercial from voice over in Audacity by adding music and sound effects is known as sound design. (To learn how, go here.) Once you’ve added all the voice and sounds into Audacity, click the File Menu and save it all as a project.

Eventually, you will export your work (the option underneath Save Project), but always keep all your tracks and modifications saved as a project separately.

If you are going to modify a track, such as your voice over, first duplicate that track, drag it down to the bottom of the project, and mute it. This is just so you have easy access to a backup of the original track before you started modifying it. To duplicate, select the track (double-clicking anywhere in the track will work) and then use Ctrl-D (Windows) or Command-D (Mac)—or click the Edit Menu and choose Duplicate.

Your main goal in saving your project workspace (vs only saving the exported file) is to be able to go back and make changes later, even after you export your final draft of the commercial.

Exporting and Sharing

If you don’t know what format the client wants, export as a .wav file (large) or high-quality .mp3. Because the mp3 format is patented and Audacity is a FREE sound editor, the first time you try to export in mp3 format Audacity will show you some simple install steps. Simply follow those steps, or watch this video.

To share your work on social media, you will often have to convert it to a video (mp4 is a common video format that will work everywhere) if you want it to play inside the social media post. That means, at a minimum, choosing a static image that will be visible in the video while your audio plays. To find an image that gives you the rights to do this, try Pexels. To convert your audio to video with the image you choose, use ez-converter.

2. Control Clipping at ALL Stages

Oversimplified, clipping is audio distorted by being too loud. The rounded top or bottom of a waveform is “clipped” off. When you are viewing audio in Audacity, clipped areas appear red (IF you have set Audacity to make clipping visible, see next paragraph). Here is an example of viewing the same clipped audio at two different zoom levels:

  

Audacity can fix mild clipping, and it’s particularly good at fixing clipping in voice-only recordings. The first step is to see where clipping occurs—turn on “Show Clipping” at the bottom of the view menu. Simplest is show clipping all the time. (Alternatively, you can have Audacity search for clipped areas by using the “Find Clipping” Analyze function.)

Control during recording

When recording, you will adjust amplitude levels (louder or softer) using knobs on your mixer (these knobs are sometimes called “pots”, short for “potentiometers”).

If your mixed has BOTH a level AND a gain knob (check the labels on the mixer itself) set the “Level” knob midway between max and minimum (usually straight up) and turn up the “Gain” knob until your voice at normal volume is clipping often—but not all—of the time. Then turn down the “Level” knob until your voice is sometimes but rarely clipping. Occasional clipping is better than setting levels too low; very low levels will can over-amplify background noise. (If your mixer has more than one channel, make sure you are adjusting the channel your microphone is plugged into.)

Control during mixing

When you add music and sound effects, you may have to quiet everything 1dB or so, or the power of voice and music combined may clip a bit too much. Fortunately, it’s easy to see what is going on and adjust accordingly.

tracks > mix and render to new track

Here’s a simple way to tell: Select all (keyboard shortcut: ctrl-a/Windows; command-a/Mac) and then mix everything down to a single new track (picture at right: Tracks Menu > Mix > Mix and Render to New Track).

If there isn’t much that is red/clipped, select either the entire new track, or only the main areas with red/clipping, and choose Effect Menu > Clip Fix. If there’s a lot of red/clipping, delete the combined track (or just undo (Ctrl/Command-z) the new track you created) and quiet (reduce the gain) one or more of your tracks a bit. The easiest way to quiet the level/gain of a track overall is to drag the +/- slider at the left edge of the track.

3. The Magic of Changing Tempo

If you want to end music or a sound effect a bit later or sooner, simply choose Effect > Change Tempo to shorten or lengthen the music! Small changes will NOT sound noticeably different, it will just make whatever audio you selected shorter or longer. Settings let you shorten or lengthen audio by a selected percentage without changing pitch.  Do NOT use the Change Speed.. effect. This WILL change pitch and make things sound strange.

While you should rarely change the length of voice audio, a smooth voice with good diction can be sped up or slowed down as much as 15% or more without making the voice sound strange. Most music and sound effects can handle even greater changes while leaving them sounding essentially the same.

Change Pitch is a useful effect in altering sound effects (SFX). SFX generally means sound that isn’t voice or music. For example, coffee pouring into a ceramic cup sounds strangely high-pitched to most ears. Simply lower the pitch of the “coffee pouring” audio for a sound that sounds more normal.

4. Use Effect > Bass and Treble to Control the Mix

Select some audio to play, and hold down the Shift key on the keyboard while clicking play to play on repeat over and over. Then click Effect > Bass and Treble… and adjust the sound while it plays. This is a great trick to help find the right blend between music and voice. Of course, you don’t want to change things too much, as you don’t want to misrepresent the voice over recording.

A common example is to increase the treble in a voice over track to help it “cut” through the music a bit. It makes some voice/music combinations seem to highlight the voice more, to make the voice more “present.” Instead of or in addition to changing volume at key spots to help the music and voice blend more to your liking, you can also apply Bass and Treble… to either or both the music and voice.

As you get older, you will hear higher pitches less, so older ears should adjust the equalizer in your computer’s audio settings (not in Audacity or on your mixer) so that you don’t increase pitch too much in your mix. Start by testing your hearing here.

However, if what you really want is to change the pitch of music or a sound effect, use Effect > Change Pitch…

5. Control “Odd” Sounds with High or Low Pass

When a voice talent “explodes” a bit too much on a “p” sound we call it a “plosive.” The rumbling sound of the air popping out from a particularly explosive “p” is a low frequency sound. To remove some of the low frequency sound, you can choose to pass through mainly higher frequency sounds. Think of “High Pass” as reducing low-pitched sounds. Scroll down near the bottom of the Effect menu to find this effect.

Similarly, if you have hissing “s” sound, you’ll want to try getting rid of some of the high frequency hissing. Select the audio and use Low Pass Filter… (think of it as reducing high-pitched sounds).

A low-pitched thump on the mic stand could be masked with High Pass Filter to reduce the low frequency “thump” sound. Just select the thump and apply High Pass.

Don’t Overdo It!

High and Low pass will change the sound of whatever audio they modify, so listen carefully to the result and use less if needed. And don’t try to eliminate problems like hiss or rumbling if they are all throughout the audio. These effects are best just for touching up small moments of problem audio.

6. Aligning Music with Voice

These are guidelines. But remember, a voice-over demo is NOT a production itself! It must seem simply like clips from actual commercials. ►Read Commercial Demos: The Rules before actually mixing music for demos. The main rule is do NOT have music before or after the voice unless less than two-tenths of a second. The voice should be the star, not the production or the music.

Which part of the music should you use?

At any point, remember you can change the music tempo (see step #3 above) if you want to match the ending up more appropriately with the voice. When starting, try these options in this order:

  1. Start the beginning of the music with the beginning of the voice.
  2. Look at the waveform of music you have picked for areas with transitions, and try having the music make a transition during the voice.
  3. Skip through (scrub is the technical term) and listen to the different sections of the music (if there are any) and try a section different than the beginning section.
  4. Try lining up the music so it’s natural ending comes when the voice ends. Music often ends too slowly to match up with a quick commercial voice clip, so you may need to create a different fade out. When using the part of music that fades out on its own, usually best for it to end before voice, but depending on music, there can be 1/10 second or so of music after voice.

Beginning and Ending Options

By default, try starting and ending music at the same time as voice. Try it first with NO fade in or out on the music, or a less than two-tenths of a second fade in/out, i.e. abrupt.

Beginning of Track: For a longer initial music fade-in, start at 25%-75% of volume, and fade in for a second or more.

End of Track: End music before voice, generally, so last thing heard is voice, e.g. ends music just before or during the last syllable, so the (very brief) last sound is the voice.

Use Effect > Change Tempo but made as short as possible without “weirding” out the voice. Typically 8-19% faster.
One where music fades after voice. This sometimes sounds best if listening to the track on its own (though not always, sometimes ending the music first sounds best).

Bonus: Complete Control of Amplitude in the Mix

The envelope tool in Audacity  takes some getting used to, but it allows you complete control of the amplitude of any track at any location. Here’s a short video introduction to how to use it and what it can do: