So, this is going to be a longer post...We're going to compare 6 different methods of noise reduction.
I get a lot of questions about cleaning up audio after recording, hums, clicks, pops, line noise, neighbors, fridge, etc. A lot of people are still trying to gate or EQ this stuff out, and those methods don't work particularly well for voice over, especially dry auditions.
Gating will turn off the audio signal when you're not speaking, which gives you perfect silence, but when you start speaking again the noise is back too. This can be VERY unnatural depending on the noise.EQ can work, but usually to the detriment of the entire piece of audio, as you are carving out chunks of the frequency spectrum. Those chunks start carving into your voice as well. Sort of like destroying the town to save the town...
Ideally you'd just want to record clean in the first place, but sometimes you just can't help but knock something out and hope you can clean it up after the fact.Noise Reduction plugins to the rescue!To test, I set up my Solaris to records in "Figure 8" mode (so the front and back of the mic are recording equally), set one side up for me, and put the other side of the mic right up against my bathroom door with the fan running.This is a worse case scenario for voice over, as fans tend to generate noise that slices right through the middle of the human voice's spectrum. That means that as you remove fan noise, you're likely carving out a chunk of the voice as well. A less extreme version of this would be a fridge kicking on or the AC running.
All of these plugins (and doing it by hand) work on the same general principal, point out what undesirable noise looks like, and try to get rid of only that noise. [Check out the Audacity Tutorial for Noise Reduction in practice - Ed.]I attacked the samples pretty aggressively with each method. For the test, the main idea was to all but eliminate the background noise, even if it damaged the voice. Real world, you would probably want to leave a little more noise to prevent damaging the recording.
So first up, here's the unaltered file:
Sony Sound Forge NR plugin:
iZotope RX De-Noiser:
Audacity NR plugin:
Adobe Audition NR Plugin:
Doin it by hand with Phase Inverse:
Waves Restoration X-Noise:
Again, this is most certainly a worst case scenario when it comes to noise reduction, and hopefully you don't encounter this much noise on a regular basis. I find the results interesting listening back. There are two methods up here which are essentially free, and the most expensive plugin comes in a pack which runs about $1000.So what do YOU think? Are there other plugins that I'm missing?
