Q. How can I remove background noise from a voice recording?

Published in SOS April 2011
Bookmark and Share

Sound Advice : Recording

Mike Senior

I've made a recording of someone talking, but there's quite a lot of background noise. How can I extract the vocals, or at least bring them out a bit to make them clearer?

Katy Majewski via email

SOS contributor Mike Senior replies: Assuming that the voice you've recorded is destined to be heard on its own, any kind of normal full‑band dynamics process, such as the expansion or gating you might use at mixdown, will almost certainly be too blunt a tool for the job. All they'll do is restrict the noise only to those moments when the voice is actually speaking, which won't help make the voice itself come through any clearer.

In the first instance, I'd therefore recommend a dedicated multi‑band noise‑suppression algorithm instead: something like the Cockos ReaFIR plug‑in (part of their freeware ReaPlugs bundle) or Voxengo's ReduNoise would be a good first port of call. These work by analysing a section of the recording where the vocal isn't present, in order to build a profile of the noise signal, which can then be used to remove the noise more intelligently. The settings of these plug‑ins can seem a little intimidating, so you'll have to get your manual‑reading cap on, but they're capable of pretty good results in the right circumstances. One tip here, though: when you first try this process, dial up the noise reduction to its most severe so that you get familiar with the strange little digital chirping artifacts it can cause. That way, when you're actually trying to decide on the best compromise between the levels of noise‑reduction and processing artifacts, you'll know what to listen for.The ReaFIR plug‑in within Cockos' freeware ReaPlugs bundle can be used to reduce background noise in a more transparent way than is possible using ordinary expansion or gating processes.The ReaFIR plug‑in within Cockos' freeware ReaPlugs bundle can be used to reduce background noise in a more transparent way than is possible using ordinary expansion or gating processes.

If this doesn't do the job adequately, and the recording in question is an important one for you, it's probably time to call in the professionals, and in this regard I'd personally recommend giving CEDAR Audio (www.cedar‑audio.com) a call. They've been at the forefront of this kind of technology for years, and run a by‑the‑hour restoration service that is comparatively affordable, bearing in mind the cost of the processors they use!  

June 2016
On sale now at main newsagents and bookstores (or buy direct from the SOS Web Shop)
SOS current Print Magazine: click here for FULL Contents list
Click image for June 2016
WIN Great Prizes in SOS Competitions!


Home | Search | News | Current Issue | Tablet Mag | Articles | Forum | Blog | Subscribe | Shop | Readers Ads

Advertise | Information | Privacy Policy | Support | Login Help


Email: Contact SOS

Telephone: +44 (0)1954 789888

Fax: +44 (0)1954 789895

Registered Office: Media House, Trafalgar Way, Bar Hill, Cambridge, CB23 8SQ, United Kingdom.

Sound On Sound Ltd is registered in England and Wales.

Company number: 3015516 VAT number: GB 638 5307 26


We accept the following payment methods in our web Shop:

Pay by PayPal - fast and secure  VISA  MasterCard  Solo  Electron  Maestro (used to be Switch)  

All contents copyright © SOS Publications Group and/or its licensors, 1985-2016. All rights reserved.
The contents of this article are subject to worldwide copyright protection and reproduction in whole or part, whether mechanical or electronic, is expressly forbidden without the prior written consent of the Publishers. Great care has been taken to ensure accuracy in the preparation of this article but neither Sound On Sound Limited nor the publishers can be held responsible for its contents.
The views expressed are those of the contributors and not necessarily those of the publishers.

Web site designed & maintained by PB Associates | SOS | Relative Media