Noisecleaning With Pics
- For the full Noise Cleaning tutorial, please visit the Noise Cleaning page.
Most of the time, a microphone will record background noise. Background noise can be anything from a slight buzz to an annoying high-pitched hiss. Cleaning up the background noise will highly improve the quality of your recordings.
How to Spot Background Noise
I always amplify before noisecleaning. I find it easier to spot noise. Background noise shows up as a fuzzy line. Things to keep in mind:
- Sometimes, when you're used to hearing the noise, it doesn't stand out that much to the ear.
- Depending on the frequency, the noise might even be practically inaudible! However, if your silences show up as a bold or fuzzy line, there is noise!
Here is what background noise looks like:
Clean up the Noise
1. Select a Noise Sample
Highlight a section of your recording that has pure background noise.
2. Define Your Selection as Noise
Tell Audacity this is the noise you want cleaned. Select Effect > Noise Removal
A dialog box pops up. Click on Get Noise Profile. The box will disappear.
3. Remove Noise
Select your entire track (Ctrl + A). Go back to Effect > Noise Removal. Now, tweak the settings.
- Set Attack/decay time to 0.01
- Set Frequency Smoothing to something around 250. (You might have to play with it a bit, though I haven't found it makes that much difference. Just don't crank it up all the way to the right.)
- Now, play with the first slider. Start at the left, click Preview (bottom left), and keep increasing the number until you can't hear any background noise. I find 10-15 DB is reasonable, but try avoid going above 20, as it might start distorting the sound. (However, sometimes, you might do quite aggressive noise cleaning and get surprisingly good results with Audacity 1.3 & later) Once you find the right level, simply click OK.
- Wait for the program to run. It might take a few minutes if it's a long recording.
Here is the Result: