How to reduce microphone noise
Background or ‘ambient’ microphone noise can be a real pain, but there are tricks to help reduce it. To some extent any sound recording will generate background noise, but there’s a lot that you can do to minimise interference. Follow the steps below for tips on how to minimise background noise from an audio recording.
WHAT YOU’LL NEED
Mic noise appears when sound is transferred from one device to another. Here’s how to reduce it:
On laptop recordings:
Windows Vista, XP, and Windows 7:
Go to Start
Select Control Panel
Open Hardware and Sound
Find the Microphone bar
Right-click on the Microphone bar, and then select Properties
Find the Levels tab, and look for the Microphone Boost tool
Move the dial all the way down on the Microphone boost
Move the dial all the way up on the Microphone
Next, go to the tab marked Enhancements
If they aren’t already ticked, tick the following boxes: Noise suppression and Acoustic echo cancellation
To test the noise, go back to the Recording menu
Go to Listen to this device
OS X (MacBook and MacBook Pro’s using OS X versions 10.4.6 and later):
Go to System Preferences
Find Sound preferences
Look for the Ambient Noise Reduction tool
Check the box marked Use ambient noise reduction
Move the dial up and down (until you find the right balance of audio output v. background noise)
Check for nearby devices which might cause interference
Switch off anything noisy (i.e. ceiling fans, televisions, laptop fans, or traffic noise)
Speak directly into the microphone
Close doors and windows
Make sure that the mains electrical cables are not running across signal cables (i.e. if you’re using a wireless mic). The same goes for mains cables and audio cables (i.e. headphone leads), because the electromagnetic force which surrounds mains cabling can cause interference.
Use the right sort of mic. A general-purpose mic won’t pick up quiet acoustic instruments or subtle sounds. You need a microphone designed to pick up difficult-to-record sounds (ask for a back-electret mic)
Use a separate microphone – not just the one in your computer
Use a digital recording device separate from your PC
On headsets and headphones
Check the headphone jack – make sure it is securely plugged into the device, and that it has been plugged into the mic jack (and not the audio input jack)
Try a different power socket – all electrical circuits produce noise
Listening through a laptop computer? Unplug the power cable and use the computer’s battery power.
Make sure the ear buds are properly inserted into your ears – windy conditions can affect the audio output
Noise reduction accessories
There are several good free online software downloads for editing video and audio recordings.
Audacity is a free online tool which is designed to isolate and remove unwanted background noise. Other good alternatives include WavePad, and Wavosaur, but you can search for ‘free noise reduction software’ on Google and experiment with different software downloads.
When you start searching, make sure that you choose a download for sound editing software and not a noise reduction tool for photography .
Mac has a feature called GarageBand which is an sound editing package designed for musicians – it comes with most OS X packages but is also available as an App on iTunes.
Use a Mic Preamplifier. This eases the transition between your Mic and other equipment (prepares it for transfer).
Invest in a ground lift adaptor for your laptop power supply – these do an excellent job of reducing static noise, particularly if you use multiple sections of recording equipment.
Fit a shock mount to the mic stand to reduce background noise cause by tremors and vibrations.
Use a wind sock – this fits over the mic’s head and cuts out unwanted wind interference.