But my radio audience never heard those sounds. I was able to edit them out using Cool Edit 2000, a relatively inexpensive ($69.95) but versatile audio editing program from Syntrillium Software (www.cooledit.com).
Although I use the program primarily to edit voice files for my radio shows, it can also be used to record and edit music and other audio and to mix different sources of audio to create a professional sounding finished product. You can even use the program to clean up existing audio programs, such as getting rid of the pops and scratches on old vinyl records or the hiss on old cassette tapes. Once you're done editing your sound file you can save it in its highest-quality uncompressed format or as an MP3, Real or other file for use on the Internet. Files created or edited with Cool Edit can also be written to an audio CD for use in any CD player.
Cool Edit lets you record sound from a microphone, a CD inserted into your PC or any external device, such as a tape or mini-disc player or even a record player that can plug into the microphone or line input socket on your sound card.
One of the nice things about editing sound on a computer is that you can see, as well as hear, the sounds. That's because sounds form a "waveform" that is visible on the screen. I don't know of anyone who can literally decipher speech by looking at the screen, but -- after editing many interviews -- I've actually started to notice the "shape" of certain sounds such as "um" and "ah," making it pretty easy to edit them out. You can also easily distinguish between quiet sounds and louder ones.
In many ways, editing sound is a lot like editing photos. You can take out the imperfections and you can even add things that weren't there in the first place. For example, Cool Edit has a "mix paste" feature that allows you to grab one sound and mix it with another. If your trio lacks a bass, you can grab the music, mix it in and suddenly you have a quartet.
You can also add plenty of special effects. If one part of your sound file is too low or two high, you can select it and use the "amplitude" function to change the volume. I've used it several times to compensate for recordings that were just too quiet to broadcast. The program also has a noise reduction feature that allows you to reduce hiss, background sounds and other noise you'd rather not hear.
There are plenty of other special features -- most of which I never use -- such as echo, delays, and the ability to adjust the frequency of all or part of a song. You can even "stretch a wave," which has nothing to do with surfing. It allows you to change the key or slow down part of a song without changing the pitch. Another popular feature is the ability to create and import "loops." A loop is an audio file that can be inserted into another file to be played continuously. Unlike regular songs, it doesn't have a clear beginning and ending.
In addition to the basic program, Syntrillium sells plug-ins that add features to Cool Edit. These include an audio cleanup plug-in that adds advanced restoration features as well as Cool Edit studio, which adds multitrack capability, turning your PC into a pretty sophisticated recording studio.
Cool Edit isn't the only program of its kind. It competes with Sound Forge Studio from Sonic Foundry ($69.97, www.sonicfoundry.com). Both Syntrillium and Sonic Foundry also offer more sophisticated versions -- Cool Edit Pro ($249) and Sound Forge 6.0. ($349.97). But, unless you're doing some very tricky and serious sound editing, the lower-cost versions should do just fine.
You can download a free-trial version of Cool Edit from www.syntrillium.com/download. You can also download some useful free tutorials to learn more about sound editing.
A syndicated technology columnist for nearly two decades, Larry Magid serves as on air Technology Analyst for CBS Radio News. His technology reports can be heard several times a week on the CBS Radio Network. Magid is the author of several books including "The Little PC Book."
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By Larry Magid