Can You Filter Out Background Noise on a Digital Recording?by Hazel Mollison
Reducing or eliminating background noise will make your digital recordings sound clearer, crisper, and more professional. It can be difficult to entirely cut out background sounds when recording, whether it's the hum of an air conditioner or sound of wind or traffic outdoors. But most audio editing software can filter out these sounds without affecting the quality of your recording.
Editing Digital Recordings
One of the advantages of digital over analog recording is you can manipulate your sounds using a computer. You can choose from a wide range of audio editing software, depending on your needs and budget. At the higher end of the market, programs such as Adobe Audition and Sound Forge give you numerous options for editing your recordings and eliminating unwanted noise. Many effective free applications are also available, such as Audacity, which can remove static, hiss, hum and other background noise.
Reducing Background Noise
The exact method you'll use to remove noise will depend on your software. For example, if you're using Adobe Audition, upload your recording and select the "noise reduction effect". In Edit view, find a section of your recording that is at least half a second long and includes only background noise. Highlight it, and choose Capture Noise Reduction Profile.Then, choose Effects > Noise Reduction > Noise Reduction, and select the part of the recording you wish to remove noise from. Most other programs have a similar function. If in doubt, consult the user manual or the program's Help menu.
Noise gates are a type of application that can reduce background noise. They work by removing audio frequency bands that are below a certain threshold, and contain only static, or background hissing or hums. If your editing software doesn't include one, you can download programs such as Floorfish. When applying the noise gate to your recording, experiment with adjusting the levels. You might need to find a compromise between reducing background hums and maintaining the quality and clarity of your recording.
Other Recording Advice
To get the best possible results, first try to reduce all background noise at the recording stage. Choose a quiet room, with few or no windows if possible. Use a microphone stand to minimize vibrations and put your mouth close to the microphone. You can also use software to reduce the effects of noise when recording. Programs such as Audacity can filter out much of the white noise, as well as reduce echos and other sounds.