Electronic Studio Resources I: Assignment 2 — Audio Editing

Assignment 2: Audio Editing

What we’re trying to do

Get used to some of the basic techniques of working with audio in Digital Performer:
- setting up a new project,
- importing sound files into the project,
- placing a new soundbite — a segment of a sound file — into a track.
- editing the soundbite (moving, trimming, extracting, etc.),
- and fading your edits to avoid clicks.

What to turn in

One Digital Performer project folder, with the assignment number and your login as part of the folder name. Drag the folder into the Drop Box folder for Assignment 2 on the computer in the studio.

The basic process

The source material comes from sound files I have provided for you. These are excerpts of well known people speaking. Your job is to cut up and recombine the speech so that these people say things they didn’t mean to. This requires you to listen carefully to what they’re saying, write down some interesting possibilities, and then edit the material in Digital Performer.

You should edit the speech so that each soundbite contains no more than 2-3 words.

At the same time, try to make the result as musical as you can. What could possibly be musical about people talking? Think about the rhythms and contours you create with their extracted words. Try to make sequences of words that are like musical phrases. Have some places where the audio clips run together smoothly to create a convincing sentence. Have other places that are choppy but timed in an interesting way. (Think about the mysteries of comic timing.)

You should try to come up with 40-60 seconds of material. You can get by with a shorter sequence if the editing is very fast-paced.

Save frequently! Back up your work onto a USB thumb drive and onto the CECM server. Let us know if you’re new to the Mac and need help handling files, disks, and so on. It’s sort of like Windows — but sort of not.

Be prepared to play your sequence in the next tutorial.

Importing sound files

After you import a sound file into Digital Performer, it becomes a soundbite. (For more on soundbites, see below.) You drag soundbites into audio tracks to build a sequence. You can drop a soundbite into your sequence any number of times.

Launch Digital Performer (DP) from the Dock (bottom of the screen) by clicking on its icon.
Create a new DP Project using the menu command File > New > New. Save the project in your Documents folder or on the Desktop.
A new sequence file might already have some empty audio tracks. The tracks are either stereo (for 2-channel audio) or mono. The number of squiggles next to the track name tells you which (1 for mono, 2 for stereo).

You can use stereo soundbites only in stereo audio tracks, and mono soundbites only in mono audio tracks. The files you use in this assignment are mono, so make sure you have severeal mono tracks.
If you need more tracks, create them by choosing Mono Audio Track from the Project > Add Track menu.
In the Finder, open the “Course Materials” folder on the Desktop. Inside you’ll find an “Assignment 2” folder containing the sound files to work with.
The easiest way to get a sound file into your project is to drag it from the Desktop into an appropriate audio track.

When you see the light blue rectangle, release the mouse button to drop the file into that track. Digital Performer won’t let you drag a stereo sound file into a mono track, or vice versa, and it won’t let you drag a sound file into a MIDI track.
The imported audio file appears in the track as a new soundbite; the soundbite refers to the entire duration of the audio file you imported.
When you import sound files, Digital Performer automatically copies them into the Audio Files folder inside of your project folder.
Play the sequence. (The space bar toggles playback; the ‘1’ key on the numeric keypad rewinds to the beginning.)
Once in your sequence, the soundbite appears in the Soundbites cell (an area of the window), which you can view by typing shift-B. As you edit soundbites, Digital Performer will create more entries in the soundbites list. You can place an instance of a soundbite into a track by dragging its move handle (the squiggly shape in the MVE column of the Soundbites cell) into a track.

In the Soundbites cell, you can click on a soundbite name to hear the soundbite.
CAUTION: If you double-click, instead of single-click, on a soundbite name in the Soundbites cell, then you’ll open the Waveform Editor, a destructive audio-editing environment. You don’t want to do anything destructive now, do you? Close that window before it’s too late.

Project Folder Organization

It’s important to keep your project folder organized, because otherwise you will have problems with lost sound files later.

A project folder contains a sequence file, as well as folders for sound files and other things. Because a project contains multiple files and folders, you need to be especially careful about backing up. Our recommendation is to keep everything relevant to the project inside your project folder, and copy this folder to and from your backup media as a single unit. In other words, don’t take items out of the project folder and copy them separately.

NOTE NOTE NOTE
You should run your project only from the local hard disk (i.e., the hard disk in the computer or an external hard disk attached directly to the computer), not from servers, flash drives, or CDs. Even though this may work some of the time from a server, it’s usually too slow to be reliable, and you will certainly not be able to record reliably to the server. You might hear audio drop-outs, or Digital Performer might complain about not being able to run all the audio effects you want.

To reduce the chance that Digital Performer will use a sound file on our CECM server or on your USB drive, instead of one on the local hard disk, eject all servers and other disks before opening your sequence file.

Editing with Soundbites

Open the Sequence Editor by double-clicking an audio track in the Tracks view. You’ll need to make the DP window bigger, by dragging its lower-right corner, and also move the divider between the Sequence and Tracks views, so that you can see your tracks well.

The Sequence Editor shows all tracks, including Conductor and MIDI tracks, in one view. This is where you’ll do most of your soundbite editing.

You can hide and show tracks in the Sequence window by clicking on track names in the Track Selector, which you can show by choosing Track Selector from the Studio menu.

There are many ways to edit with soundbites, copying and moving them around, as well as creating new soundbites that have different dimensions.

Here are some of the more common editing techniques.

Drag a soundbite to move it to another place in the same track or to move it to a different track. Pay attention to the Snap to Grid settings in the upper right part of the window.

These let you choose a note value for a grid. When the grid is on (box next to note value is black), then dragging soundbites will be constrained to the increments of the note value. You can quickly toggle snapping on or off by holding down the Apple key when dragging.
Option-drag — hold the alt/option key down while dragging — a soundbite to place a copy of it in another track or at another time in the same track.
CAUTION: Click in the waveform part of the soundbite, not on the name of the soundbite, when you have the option key down. If you option-click the name, DP lets you type a new name for the soundbite.
Control-drag a soundbite to make it snap to the edge of another soundbite.
Option-control-drag a soundbite to copy it and snap the copy to the edge of another soundbite. This is a way to make repetitive patterns.
To extract audio from one soundbite into new, shorter ones...
- Open the soundbite for editing by double-clicking it. The cursor becomes an I-beam.
- Make a selection by dragging in the soundbite with the I-beam tool. The segment you select will play immediately. Hold the shift key down while clicking on another part of the soundbite to extend or shrink the selection.
- Edit > Copy.
- Set an insertion point at an empty place in a track by clicking there with the crosshair (+) tool.
- Edit > Paste.
Use the Split command (Edit menu) to break one soundbite into three separate soundbites. First double-click a soundbite and make a selection, then use the Split command.
You can change the dimensions of a soundbite by edge-editing. This means dragging the left or right boundary of a soundbite to reveal or exclude some of the underlying audio file. Move your mouse over the left (or right) edge of a soundbite: your cursor changes to the edge-edit cursor.

Now click and drag. This changes the start (or end) time of the soundbite, relative to the start of its sound file.
NOTE: When edge-editing, don’t drag the edge near the top of the soundbite, since that time-scales the soundbite instead.
By default, edge-editing affects the current soundbite and all instances of it in any track, as well as future instances. If you don’t want the soundbite you edge-edit to affect other instances, first click on it to select it, then issue the Audio > Duplicate command. This makes the soundbite you select unique — independent from other instances of it.

The soundbites Digital Performer creates when you import a sound file refer to the entire file, whereas the soundbites you make when editing usually refer to just part of the file. When you edit soundbites, Digital Performer often creates new soundbites without you knowing about it. This is convenient, but sooner or later you’ll want to manage your huge list of automatically created soundbites. In the Soundbites view, look for the Mini Menu triangle, and click to get a pop-up menu.

Choose Select Unused Soundbites from this menu, followed by Remove From List or Delete Soundbite (careful with that one). Try using the View By pop-up menu. Rename soundbites and sound files by option-clicking their names in the Soundbites cell.

Preventing Audio Clicks

If you’re listening carefully, you’ll probably hear clicks at the start or end of some soundbites. This usually happens when there is a sharp discontinuity in the waveform — a common occurrence when splicing bits of audio together. Sometimes you also want to crossfade two adjacent soundbites; this smooths the joint between them.

You get rid of clicks by applying a volume envelope to a soundbite. Even a very quick, barely noticeable attack or release can suppress a click. The best way to create these envelopes is to use fades.

To create a fade, select a brief time region overlapping the start or end of a soundbite, then invoke the Audio > Fade command. Make your selection in the Sequence Editor for precision.
There is a graphical shortcut to using the Fade command: move the mouse over the edge of a soundbite, in the area just between the waveform display and the colored title bar. When you see the crossfade cursor, click and drag toward the middle of the soundbite to create a fade (or crossfade).

This may strike you as an obscure consideration, but to get professional results, you’ll have to deal with the problem of clicks sooner or later.

Soundbites — What are they?

In Digital Performer, you work with the audio in a sound file using soundbites. A soundbite is a reference to a portion of a sound file on the hard disk. For example, say you have a sound file called “locomotive.aif.” It’s a 30-second recording of a steam engine, which blasts its whistle for 10 seconds during the middle of the recording. You could make a soundbite, called “whistle,” that refers just to the portion of “locomotive.aif” during which you hear the whistle.

The soundbite stores the start time of the whistle, relative to the beginning of the sound file, and the duration of the whistle. (You can see the duration in the Soundbites window.) When Digital Performer plays this soundbite, it looks up the timing information in the soundbite, and then uses it to read just the specified portion of the sound file.

Here’s the important part: the soundbite does not contain a copy of the portion of the sound file. In other words, the soundbite does not contain audio samples copied from the sound file. It just contains two references — start time and end time — to the sample data in that file. This means that the soundbite doesn’t take up very much memory or disk space — nowhere near the amount used by the audio data. It also means that editing soundbites is very fast, because only the start-time and end-time references must change, not the actual audio data in the sound file. Soundbites are the cornerstone of Digital Performer’s non-destructive editing environment: they make it possible for you to cut and paste bits of audio without ever altering the original sound file.

NOTE: Soundbite is a Digital Performer term. The same thing is called a region in Pro Tools.