Noise Reduction shoot out - Sound Forge, iZotope, Audacity, Audition, Waves, and doin it by hand!

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?

Apple forcing us to turn down the volume?

So, this story isn't new, been floating around teh intarwebs since before Xmas (and I've written about this before), but I still think it's worth taking a quick look at.
The Telegraph reported on Dec 23rd, that Apple has filed a patent that would allow future iPods to calculate how long you've been listening to music, at what volume you've been listening, and would gradually turn down the volume on you. This is supposed to be a big magnanimous gesture on Apple's part, as people can plug into music all day long thanks to huge amounts of storage available. As hearing loss can be a gradual event, most people might not even know they're doing damage.
This idea sounds great in theory (like a rev limiter on car helps save fuel and forces you to not do something too stupid), but I see some huge flaws.

First off, will this be a feature we can turn off? It sounds like a silly question at first, but Apple has shown a tendency (as do a lot of tech companies) towards locking consumers into doing things their way because they "know better" (iPhone I'm looking at you). If Mommies and Daddies get concerned about little Timmy's Nano, Jobs & Co could make this a new locked in "feature" to assuage concerns, or make it painfully difficult to disable.
Why would I want to turn it off? Well the majority of the time I listen to my iPod it's usually plugged into speakers of some kind. Also I hate proprietary docks and connectors, so I plug my Nano in using the headphone jack. In my car I have a line in, and at home my stereo has an "MP3 port" (which is just a fancy way of saying "line in"). In both cases I'll jack the Nano to about 80% volume and then control the actual speaker output via the stereo. If this system is monitoring the ipods output it's going to think I'm blasting my ears for hours at a time. I don't want to be fighting my MP3 player while driving...

Secondly, this issue with people listening to music too loud for too long is mostly Apple's fault at this point. A lot of people credit the success of the ipod with the distinctive design of the white earbuds. Well guess what? Those are HORRIBLE for your ears! They don't create any seal around the ear's opening, so your music is constantly having to compete with the sounds around you. The louder the noise, the louder you'll have to turn up your music. The ipod is a fantastic DAP. The headphones included are the worst dime store crap you could put in your ears.
If Apple really cared about protecting people's hearing, they would drop these headphones immediately, or would include an accessory like the Griffin Ear Jams to help with the problem. Even the Zune includes "premium" headphones which help with noise cancellation, and should allow people to enjoy music at lower volume.

When I do listen to Nano with headphones, it's either on Sony EX51's (pictured) or Sennheiser cx300's. Even when working out, I have a hard time listening above 50% volume, which according to the Telegraph (sidebar), is about as noisy as a loud restaurant or office building, and shouldn't damage the ears for about 24 hours of listening. That's a lot of music...



Check out the article @ The Telegraph. It is an interesting read, though I really think Apple might be missing the point.

Make Your Own Noise Canceling Headphones

I have a lot of fun with vid sites like Metacafe...

So I get the idea behind this vid, putting nice headphone parts into closed back earmuffs, but is this really better than say picking up a beautiful pair of cx300's?



I'm not a huge fan of active noise reduction. You have to keep a battery around, and it only reduces constant noise (like the droning sounds of an airplane), and not sudden noises. But hey, Passive NR is Passive NR right? You're just blocking noise. I just happen to prefer inner-aural, "in the ear" headphones.

So anywho, this guy's discovery of clipping together headphones and shooting range earmuffs is pretty sound...


Headphone Hack! Make You Own Noise Eliminating Headset! - Awesome video clips here


Heh-heh, "pretty sound" ... I'm teh funnie...

Calling all Engineers! FAVORITE NOISE REMOVAL???

Get it? All Caps, since I'm yelling over the noise.

So, I use two PC's. I've almost always used Sound Forge (currently on v9) to do my sound design work. Recently I've been hearing all about how Audition is awesome, and I should totally switch.
I downloaded the demo and started tearing into it, and it's nice, but I can't see what the advantage is.

Sadly, AudioGuy is developing a reputation as the "GoToGuy" for cleaning up other peoples mistakes. While I'll never speak ill of working, it bothers me that I can't seem to get hired to just prevent the mistakes in the first place. Lately a lot of my work has been in cleaning up audio for low budget shorts and podcasts, and a lot of that cleaning has been noise removal. Bad mics, improper Lav placement, uncontrollable environment, bad ADR, theres a lot of noise out there.
So, throwing some files I'm working on into Audition and cranking up the NR plugin, I have to say I was a little disappointed.

Spectrum view is cool. I haven't seen yet where it really is better than waveform, just brings different information to focus first. Selection of noise to remove is great, but the actual settings to remove the noise just dont do it for me. Compared to the SF/Sony NR plugin, it's just too easy to hollow out the piece I'm working on.

So I put this out there to anyone who might catch it. What NR plugin SHOULD I be looking at? Since a lot of my freelance work involves cleaning, if something can really outperform SF/Sony, I'd love to give it a shot!