diting your sound can be one of the most exciting parts of creating sound for the Web. Download an audio editor and start playing around with it?you’ll see fascinating options for decreasing your file sizes, cutting certain sections of your sound, toning down the bass and treble, creating sound effects, or just speeding up and slowing down your sound.
Depending on your editor, you can stretch or shorten the time your sound takes to play or change the pitch so that your voice sounds like a chipmunk or a robot. You can copy the first part of the word and then paste it at the beginning several times to get a Max Headroom stuttering di-di-digital effect. You can play the entire sound file backwards if you’d like. In fact, there are so many options for manipulating sound with an editor that we can’t even begin to discuss them all. In this section, we review some of the more common editing processes?the ones that will truly enhance your sound files for the Web.
- Compression shows you how to perform the most important editing process?reducing your file sizes for the Web.
- Cutting describes how to delete unwanted sections of your sound file.
- Equalizing shows you how to obtain a proper ratio of treble to bass in your sound files.
- Normalize describes how to boost or tone down the levels of your audio file.
- Changing playback rate describes how to alter how fast or slow your sound is.
- Sound Ideas provides examples of sounds manipulated by sound-editing software.
When working with sound files, there are two completely different types of compression. One type decreases the size of the sound file and the other reduces the dynamic range of a signal.
Unless you’re a professional sound master, the type of compression you’ll most likely be concerned with is the type that reduces file size. While reducing the dynamic range of a signal improves the quality of your sound, it isn’t a fundamental part of editing sound files for the Web. However, it is important to be aware that two types of compression exist, and to know the difference between the two. Reducing File Size
Decreasing the size of a sound file is one of the most important functions you can perform when working with audio on the Web. Uncompressed sound files do the same thing as large graphic images do?they take up a lot of bandwidth. Without compression, an audio file could take hours to download. Chances are, your readers won’t stick around that long to listen to sound clips of you reading your poetry?or any sound clip, for that matter.
Reducing File Size
You can use an audio editor to compress your sound files, but not as well as a program specifically designed for compressing sound files will.Cutting
One of the easiest ways to reduce the size of your sound file and improve the general quality of sound is to simply delete unwanted sections or random noise within your sound clip.
Most editing applications let you select parts of your sound wave, and then cut, copy and paste those sections just as you can do in an image or word-processing program.
Once you’ve opened your sound file with your audio editor, and you see a graphical representation of the sound, zoom in and listen to individual sections of the file. The “Zoom” command may be located under a File or Tools menu.
Listen to individual sections within your sound file and keep your ears open for loud “pops,” pauses where there is no sound, or sound contaminated with distortion or background noise. Chances are, those are the sections you’d like to remove.
Highlight sections of the sound clip you’d like to remove with your mouse. Underneath the “File” menu or “Edit” menu on your program, you will see options to delete or cut. Deleting portions of your sound clip makes the file a little smaller, and it eliminates noise that could be distracting to those who listen to the sound. Be careful with voice recordings?what looks like silence may in fact be a softly-spoken word. Before you delete sections of your files, listen carefully to every part of the file.
Some of the better audio editing applications include a noise gate option. Noise gates cut off audio signals that fall below a certain level, or threshold. For example, very soft sounds or background noises will not be included in your sound file. Before you record your sound, you simply set the noise gate level on your software.
The more you listen to your sound files, the more adept you’ll become at recognizing impurities within the sound file. With audio editors, you can eliminate any section of your sound file with the click of your mouse.Equalize
Equalizing your files helps eliminate pounding bass or treble in your sound file.
While some people enjoy cranking up the bass on their home or car stereos, it isn’t a good idea to do the same with an audio file for the Web. Most computer speakers can’t handle bass very well. In fact, sound files that contain only bass or only treble frequencies rarely sound as good as a file that contains both frequencies together.
One way to tone down the bass, and assure that the bass and treble match each other in the level and strength of sound, is to equalize your files with an equalizer.
An equalizer is a flexible, precise tone control located in an audio editing application that contains bass and treble controls.
An equalizer divides bass into specific frequencies that you can boost or decrease. Each of these divisions is called a band. Some equalizers have 512 or more bands of control. You use your sound application software to adjust these levels.
You can, if you wanted to, increase the bass on your sound files, but for the Web, your files will sound better if you tone down the bass. Equalizing your files can also help bring out a certain part of your sound file, such as a voice, or one particular instrument.Normalize
Normalizing increases the level of the entire sound file so that the loudest part of the sound is at the maximum playback level before distortion; it then increases the rest of the sound proportionality.
Most sound editors have a function called normalize and the program automatically normalizes your sound files.
When you normalize a sound file, you first chose the level you’d like to raise your sound to?it could be the maximum level, which is 0db, or a percentage of the maximum level. Many audio experts believe it’s a good idea to normalize a file to 96% of it’s maximum level. Doing this compensates for other people’s computers that may not respond to sound levels the same way your computer does. In theory, normalizing a file to 100% should allow the sound to be played back at the highest possible level without distortion. In reality, normalizing a file over 96% of the maximum level creates distortion on some people’s computers.
A drawback to normalizing files is that by normalizing sound, you increase background noise. Professional sound masters equalize their sound files before normalizing them, to eliminate as much background noise as possible before normalizing.Changing Playback Rate
To create Alvin and the Chipmunk-types of effects or turn your sound into a s-l-o-w motion sound, try speeding up or slowing down your sound file with your audio editor.
Most audio editing programs include functions for speeding up and slowing down sound signals. In the Tools or File menu, you can specify how fast or how slow you’d like your sound to be. If you want to get really fancy, you can draw lines with your mouse over specific sections of sound, and control the speed for specific areas of the clip only; such as speeding up only the middle part of a sound file.
Altering the speed of a sound clip can completely change the atmosphere of your Web page. Using very slow sound for a page on dreams could intensify a sleepiness effect, and using a clip of fast-paced music could help convey a frenetic mood for a site on dance clubs.
As with any audio editing process, experimenting with the pace of your sound can leave you with sound clips that truly enhance your Web site.Sound Ideas
In this section, you can hear sounds that have been manipulated with audio editing software.
We took an original sound file and altered it with audio editing software for this section. Listen to the individual differences in each clip to get an idea of how specific audio editing functions can change sound. To hear each sound, click on the link and wait for your Audio Player to open and play the sound.
- The original sound file. This file is a 44 HZ and a 16 bit resolution file (44/16), and is a good reference to what a CD-stereo quality sound sounds like. You’ll need Apple’s Quicktime to listen to this sound, as it’s a .mov file. But don’t say we didn’t warn you: this file is a whopping 723 KB. Needless to say, it might take a while to download.
- The original sound converted to 11/8 mono. (46 KB; .wav file).
- The same sound file pitched down for a slow playback rate. This effect can be created with a playback rate function on your audio editing application. (46 KB; .wav file).
- The sound file with a very high playback rate. This effect is created with a playback rate function in your sound editing application. (46 KB; .wav file).
- The sound file sped up in the middle. This effect is created with a playback rate function in your sound editing application. (37 KB; .wav file).
- The same sound file with echos in the background. You can create echo effects with an echo or reverb function within your audio editing application. (46 KB; .wav file).
- The sound files with only the treble frequencies. Once either the treble or the bass has been removed from a sound file, you cannot put it back into the file. However, if you have a sound clip in which either the treble or bass dominates over the other, you can even the two out with an equalizer, which can be found in your audio editing application (46 KB; .wav file).
- The sound file with only the bass frequencies. (46 KB; .wav file).