When it comes to noise reduction tools, there are plenty of options out there, ranging in price from very affordable to extremely expensive. Paul Maunder takes five of the more cost-effective solutions and pits them against each other in a comparison test - which do you think performs the best?

Four pieces of problematic audio were used for this test, each exhibiting a different noise or distortion issue. The first file includes 50Hz mains hum with harmonics, the second includes severe crackle, the third has been recorded too hot and clips quite badly. The fourth example has general broad frequency range background noise. You can listen to each of the 4 unprocessed examples below:

For this test, the following plug-ins were used:

• iZotope RX Elements consisting of De-hum, De-click, De-clip and Voice De-noise

• Acon Digital Restoration Suite 2 consisting of DeNoise2, DeHum 2, DeClick2 and DeClip2

• Acon Digital Extract:Dialogue

• Waves Clarity Vx standard edition

• Antares Autotune Soundsoap

The iZotope and Acon Digital suites of plug-ins both provide a similar collection of noise reduction tools as four separate plug-ins offering reduction of hum, clipping, clicks and noise. Acon Digital Extract:Dialogue automatically differentiates between dialogue and noise but nevertheless offers a simple set of controls to adjust the sensitivity and amount of attenuation.

Waves Clarity Vx provides the simplest interface of all the plug-ins included in this test with only two controls to adjust; ‘Neural Network’ which is essentially a choice of 2 processing algorithms, and the ‘Ambience/Vox’ dial which controls the amount of noise reduction. Other than that, it differentiates between noise and speech by itself and doesn’t need to learn the noise profile.

Antares Autotune Soundsoap is only available as part of Antares Autotune Unlimited and offers De-Hum, De-click, De-clip plus voice & spectral de-noising in a single plug-in interface.

Each of the noise samples in this test was processed with the appropriate tool from each plug-in. Of course, Waves Clarity Vx mostly does its own thing so in this case it was a case of just setting an appropriate amount of noise reduction and choosing the best algorithm of the two available. The one file which wasn’t processed with either Waves Clarity Vx or Acon Digital Extract:Dialogue was the clipped audio file because neither of these tools offer a de-clip function.

For this test I attempted to get the best result possible with each plug-in and tried to strike the best balance between noise reduction and artifacts. To reflect the common time pressured workflow for reducing dialogue noise, I imposed a time limit of 2 minutes in which I had to get the best result possible for each example. More details of the test are described in the following video.

The processed examples below have been randomised from one example to the next and labelled A to E. Most of them aren’t perfect by any means but are representative of what’s possible with the tested plug-ins in a short time frame. It should be noted that the audio exhibiting severe crackle is a major test for any noise reduction software and so this was definitely a case of noise reduction rather than elimination.

More than one of the processed examples for hum removal took a while to ‘kick in’ and hum is still heard at the very start of the processed audio in those cases. It’s hard to say why this happens but it does so what you hear is a true reflection of how these plug-ins fared in this task. For each one, the Audiosuite version of the plug-in was used in Pro Tools and the rendered files were then exported at their native sample rate of 48kHz at a bit depth of 24 bit.

Take a listen to each example below and vote on which one you think is best. The results will be revealed soon!

Hum

Crackle

Clipped Audio

Broadband Noise

I intend to follow this article up soon with another test where I’ll compare some of the popular, higher priced noise reduction solutions. Check back soon for that!

The results are in! Check out which plugin Production Expert readers voted for in our results article here.