Noise Free Audio Recording for Free
As e-learning professionals every day you come across situations where you have to do quick audio recording for a course. In an ideal situation you will have access to a sound proof studio with mixing consoles and so on.But in real world most probably you will have a laptop with PC microphone and will be carrying out the recordings in some conference/discussion room.
The question is does it make a great deal of difference? In my opinion, NO.
Today even the consumer quality sound equipments and on board sound cards are quite capable of meeting every day needs. As long as you are not targeting for a theatrical release any computer with a soundcard and any consumer quality PC microphone is good.
However, the most common problem encountered during this type of recording situation is the background noise, such as humming of the air-conditioning system. This can easily ruin, otherwise, a perfect recording.
Here is a simple process for removing background noise and achieving crystal clear audio recording.I will be using Audacity a free audio editing tool in this example. You may download the same from http://audacity.sourceforge.net/download/
Step 1
Open the audacity interface and hit the Record button.
Step 2
Record a few seconds of background noise. Do not speak into the microphone during this period.
Step 3
Select the audio track by pressing Ctrl+A key combination on your key board.
Step 4
Click ‘Effect’ from the top bar and from the drop down select ‘Noise Removal’
Step 5
The ‘Noise Removal’ window will appear. Click the ‘Get Noise Profile’ button. Audacity will learn what is to be considered as noise based on the sample you have recorded.
Step 6
Now, open the track you want to clean and repeat step 4. The only change here will be that you will click the ‘OK’ button this time instead of ‘Get Noise Profile.’ Please note that this button may also appear as ‘Remove Noise’ based on the version of Audacity you are using.
You can experiment with the sliders to achieve the desired quality. In my suggestion you should keep the ‘Noise Reduction’ at 10 db and keep other parameters at default level. But, feel free to experiment.
Step 7
On clicking ‘OK’ Audacity will clean the track by cancelling all sounds in the frequency range of the sample provided by you and thereby creating a background noise free audio track.
That’s about it. Just a note, this method works well with constant noise like humming of air conditioner or some machinery but won’t work with uneven noises like ringing of a telephone or sound of a door closing.
