Digital Audio: CoolEdit 2000

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Instructional Technology

Creating Digital Audio with CoolEdit 2000

This document contains instructions on the basics of creating and editing an audio file using CoolEdit 2000.  CoolEdit is installed on each of the computers in the ITRC, both as in its original form of CoolEdit 2000 and the advanced form of Adobe Audition (Adobe bought out the rights for CoolEdit Pro, and Audition is the re-branded result). The following instructions should work for either program.

Creating a New File

To create a new audio file in CoolEdit 2000, click on File|New .  You'll then see the following dialog:

Illustration of CoolEdit New Waveform dialog  

You'll note that you've got a number of choices.  If you're recording music or your audio file is destined to be put onto a CD, you'll probably want to set the Sample Rate to 44100, set the Channels option to Stereo, and set the resolution to 16-bit.  This will give you CD-Quality audio.  

Ordinarily, though, you're not likely to need such high fidelity.  If your objective is to make a voice recording for the web, you should find that you'll be able to produce clear recordings with sample rate of 22,050Hz.  You'll also be able to set the Channels option to Mono, if all you're recording is a spoken track.  But you should probably leave the resolution set to 16-bit, if only because the lowering in audio quality at 8-bit is significant.

Once you've made your settings, click the OK button.

Your next step will be to adjust the audio levels to ensure not only that you'll be able to record from the source you'd like, but that your recording levels won't be set too high or too low.

Setting the Recording Levels

Setting the Recording Levels involves both CoolEdit and the Windows Audio Mixer.  In one, you'll monitor the recording levels while you send sound through the system: in the other, you'll make adjustments to ensure that your desired input is delivering as much (but not more) volume than you need.

To begin, click on the Options menu in CoolEdit and make sure that there are checkmarks beside the Monitor Record Level and Show Levels on Play and Record options. 

Illustration of the Options Menu in CoolEdit

Once you've selected Monitor Record Level , you should see a recording level indicator at the bottom of the CoolEdit screen.  It's likely to be oscillating a bit: this is normal.

Illustration of the Recording Level Monitor

On the right side of the recording level monitor (illustrated above), you'll find that, following the zero, there's a vertical line followed by a split bar: your object in setting the levels is to adjust your input volumes until the red lines peak just before the zero.  Detail from the record level monitor window

To set your recording level, you'll want to open the Windows Audio Mixer:  you can do so by double-clicking on the speaker icon in your system tray (lower right part of your windows screen), or by selecting Options|Windows Mixer... from CoolEdit's menu.

The Windows mixer dialog shows, by default, a view of the output volume options.  

Illustration of the default Windows Mixer dialog

If your particular dialog doesn't show the same options as those illustrated above, you can view them (and others) by selecting Options|Properties from the mixer dialog:

Illustration of the Windows Mixer Properties dialog

You won't need to make any changes to the Mixer device   field: this simply indicates the sound card you're working with. You may, however, want to adjust which volume controls are visible, putting a checkmark in every box for which you'd like to see a volume control.  When you've finished, click OK, and you'll see the main Volume Control dialog. 

If you're going to be recording from a microphone, it's usually a good idea to put a checkmark into the Mute field in the Microphone's volume settings.  (Otherwise you run the risk of having the microphone's signal feed back--and that's something you'll want to avoid...)  

Illustration of muted Microphone volume

So far, you haven't adjusted the recording volume. It's now time to do so.  Select Options |Properties from the mixer's dialog, then select on Recording , and click on the OK button.

You should find that the mixer dialog window now has the heading of Recording Control .

Illustration of the Windows Mixer recording controls

In this window, you'll be able to adjust  the individual recording levels for the audio devices that may be attached to your system.  If you're recording from the Microphone , for instance, you'll want to put a checkmark into the Select field, and adjust the volume on the Microphone slider.  Speak a few words as you're making your settings:  you should see the red bar in the underlying CoolEdit program move with your voice.  If the level is too high, you'll see the red bar crossing the zero line, and you'll want to bring down the volume; if it's too low, you'll want to bring the volume up.  Your peaks should be as close to zero as possible without crossing the line.

Illustration of peak level settings  

Tip: If the levels peak over zero, CoolEdit retains a red marking above the zero line. To remove the marking so that you can tweak the level, click on it once and then return to your recording control to adjust the setting.

Another tip: You can reduce the ambient noise being sent to the soundcard by removing the checkmark from any device you're not using in your recording.

Once you've set your recording levels, you've got only one step remaining before you can begin the actual recording: click on the Stop button in CoolEdit to turn off the recording level monitoring. The Stop button in CoolEdit

Recording audio

After you've adjusted the recording levels, you can begin your recording by clicking on the Record button:

The Record button in CoolEdit

While you're recording, you'll see the recording level indicators moving, and you'll also see a time indicator in the center of the bottom of the screen showing the running duration of your recording.

Illustration of the Recording Time Indicator  

Tip: If you're recording spoken text from a microphone, don't worry too much about making small mistakes.  If you catch yourself making a mistake, simply begin the sentence again and keep going.  Editing out errors isn't difficult.

Once you've finished your recording, click on the Stop button.  Your waveform will then be drawn onto the screen, and you'll be in a position to save and/or edit your file.

Saving the Audio File

Before saving your audio file, you should consider whether you've finished editing the file, what it's going to be used for, who's going to be using it, and how it's going to be accessed.  

Saving a Work-In-Progress 

Generally, you'll want to save as a Windows PCM *.wav file. This is an uncompressed format, and thus one which won't find you needlessly sacrificing any audio quality in the editing stages. 

Saving a Finished Work

It's usually a good idea to save a master copy for yourself in the Windows PCM wav format. This way you'll have a clean uncompressed copy on hand if you ever want to edit the file or save it to another format. 

Other file saving considerations are worth mentioning, though, and these are substantially contingent on how the end-user (if someone other than yourself) will gain access to the file.  

  • If you're planning to create an Audio CD, use the Windows PCM wav format;
  • If you're planning to simply include the file on a CD, and if space permits, save the file in a Windows PCM wav format for Windows users, and in the Apple AIFF format for Mac users.  To cover all bases, see the option below, as well.
  • If you're planning to embed the file into a web page or e-mail the file, you've got several options:  the RealAudio rm format creates highly compressed files that can be played using RealAudio's player; the MP3 format can create high-quality and highly compressed files (don't use these on our website, though). The streaming Windows Media format (Windows Media Audio - wma ) also creates high-quality, highly compressed files, although it is not an option in CoolEdit: the conversion is a straightforward one using the Windows Media Encoder or the Windows On-Demand Producer .  Our streaming media server can deliver Windows Media files: it cannot stream the other formats.

Editing an Audio File

CoolEdit makes editing audio files a relatively intuitive and straightforward process.  This document covers some of the most common of the editing tasks: 

  • running noise reduction to reduce (or eliminate) tape hiss or ambient noise
  • cutting sections from an audio track
  • moving sections within an audio track
  • copying and pasting between audio tracks

Reducing Noise

The first step in editing a sound file is often running a noise reduction pass on the entire file to eliminate as much of the recordings ambient noise as possible.  Doing so involves only a few steps.

First, select a portion of the audio file that contains nothing but background noise.  You may find it easier to locate a particular segment of the clip by making a rough selection, clicking on the  Zoom to Selection button, and then making a precise selection.

Illustration of the Zoom to Selection button

You should try to select a portion of the file that contains only ambient noise, since anything matching the sound pattern you've selected will be treated as noise.

Illustration of a selection for noise reduction

Once you've made your selection, pick Transform|Noise Reduction|Noise Reduction from the CoolEdit menu.  You'll see the following dialog:

Illustration of CoolEdit's Noise Reduction dialog

In order to have CoolEdit recognize the selected noise pattern, click on the Get Profile from Selection button. (If the button isn't enabled, you can either click the cancel button, make a larger selection, and try again, or you can reduce the value in the FFT Size field: bear in mind that the accuracy of the noise reduction diminishes if this value gets set too low.)

Once you've generated the noise profile, click Close and then select the entire waveform by picking Edit|Select Entire Wave from the menu. 

Now that the entire wave is selected, select Transform|Noise Reduction|Noise Reduction from the CoolEdit menu.  You will again see the noise reduction dialog, but it should now have your previously set noise profile displayed in the window:

Illustration of Noise Reduction dialog showing noise profile

Click OK , and CoolEdit will remove that noise profile from your audio track.  

Once the process has finished, play back your audio track.  It should sound, well, less noisy.  There's a chance, though, that if your noise sample included sounds which didn't fit a predictable pattern, you may wind up with a warbling, distorted sound: if this is the case, select Edit|Undo , return to the Noise Reduction dialog (Transform|Noise Reduction|Noise Reduction ), reduce the Noise Reduction Level to a lesser amount and click the OK button.  This will cut down on the noise reduced, but should also reduce the distortion created.  If you still find that the results are unsatisfactory, select Edit|Undo again, and begin the entire process from scratch with the selection of a new (ideally, a different) sample from which you can set the noise profile.

Editing a Wave

Making a Selection

Most of the functions you'll be putting to use as you edit a wave file will involve selections from the audio file: as such, it's important that you understand how selections are made. It's done just as it would be done in a word processing program: you simply click the left mouse button and drag across the representation of the wave file.  

Sometimes, you'll want to get a closer view of the waveform in order to make your selection: clicking one of the zoom buttons at the bottom of the CoolEdit screen will usually get you the precise view you need:

View of Zoom In button - Zoom In

View of Zoom Out button - Zoom Out

Illustration of View Entire Wave (unzoom) - View Entire Waveform

Illustration of Zoom to Selection - Zoom to Selection

Illustration of Zoom to Left of Selection - Zoom to left of selection

Illustration of Zoom to Right of Selection - Zoom to Right of Selection

When making a selection in a stereo file, you can select from either both tracks at once, or from one track at a time.  To select from both tracks, drag in the area between the represented left and right tracks; to select from the left audio track only, drag along the top of the upper wave representation; to select from the right track only, drag along the bottom of the lower wave representation.

Illustration of CoolEdit window with portion of Right audio track selected

Note: A track can be disabled/enabled for editing: this can be very useful if you want, for instance, to change the left audio track without altering the right.  Clicking on the upper part of the left track (or the lower part of the right track) toggles the enabled/disabled state of the track. 

Common Commands

As you go about editing wave files, you'll find yourself repeatedly using a number of common commands:

  • Edit|Trim - to trim a wave file, leaving only the current selection 
  • Edit|Copy - to copy a selected portion of a wave file
  • Edit|Copy to New - to copy a selected portion of a wave file to a new editing window
  • Edit|Paste - to paste a copied wave at the selection point or into a selection
  • Edit|Mix Paste - to mix the copied wave with the audio at the selection point
  • Transform|Noise Reduction|Noise Reduction - to set a noise profile and to subsequently remove noise from a selection or from the entire selected file
  • Transform|Amplitude|Normalize - to bring the highest peaks in the wave up or down uniformly to a set level 
  • Edit|Convert Sample Type - to change the file from Mono to Stereo or to adjust the sample rate 

Adding Effects

CoolEdit also lets you do some pretty zany things with effects, although just how useful these would be in most academic situations is, perhaps, subject to some debate.  But here are the ones that you're likely to want to play with:

  • Transform|Delay Effects... The delay effects options let you apply a number of amusing effects that emulate echo, reverb, flanger, and even echo chambers in which you define where the sound is in relation to the walls, the floor, and the ceiling.  There is, after all, nothing like creating the illusion that you narrated your PowerPoint presentation while standing in your shower.
  • Transform|Filters... These are probably more useful than anything in the Delay Effects category.  Using the filters, you can effectively increase treble, bass, or particular combinations of frequency.
  •  Transform|Special...  Here we're deep into playthings.  You may feel compelled, from time to time, to see whether that Brainwave Synchronizer is actually all it's cracked up to be: "The Brainwave Synchronizer can produce files that, when listened to with stereo headphones, will put the listener into any desired state of awareness."  Super. Super duper. 'Nuff said. You're probably better off running the distortion transformation and hoping to gain listeners who accidentally confuse you with a heavy metal band.  The Music option under Transform Special could prove to be useful if you've got the ability and the patience to score music in a program that's not very well suited to that purpose.