Removing NOISE from an MP3 recording using AUDACITY.

[Hugh Tyros 4]

Denn  (a friend of mine in this Forum) found an old recording he had done on his Yamaha PSR 1100 keyboard .. the first keyboard he ever had.

Below is the recording.  Listen  to this track and in particular listen to the NOISE at the beginning and at the end.  In fact, the NOISE is there right through the track, but once the melody and backing start playing, the NOISE is pushed into the background.  Not sure of the origin of the NOISE, but they worked with 'floppy disks' in those days!

Just Out Of Reach played by Denn on a Yamaha PSR 1100 keyboard

This Topic is about REMOVING NOISE, so here's an example of how to do it.

Run Audacity and 'Open' the MP3 track so the waveform is showing.
The first thing we have to do is is to give Audacity a 'sample' of the NOISE we want removed.
So click and drag with the mouse over the area of noise to highlight it.



Now go to the tabs at the top, and the one we want is Effect.
In  the drop-down box choose Noise Reduction...



In the box that comes up you will see two Steps you have to take, Step 1 and Step 2 .. and you do these separately.
Check what the settings are in the bottom section.
I have set the Noise reduction (dB) to 20 as anything less than that didn't seem to remove enough of the noise.
The Sensitivity: has to be between 0 and 24.
It's a question of experimenting a bit with the numbers and seeing what you end up with.  Any NOISE you remove will also remove some of the 'music', and it is better to leave some of the noise rather than compromise the overall sound of the music.  If you are not happy with any result you get (and this applies to anything you do in Audacity) you can click the Undo (or hold down the Ctrl key and press the letter Z), which will take you back a step to where you were before.



First time round click on Get Noise Profile.



Now that Audacity knows what the NOISE sounds like that box disappears.
We now have to tell Audacity what section of the track we want that noise to be removed from. 
Well, the whole track.

So click on the tab Select at the top, and then All.  Or, on the keypad, hold down the Ctrl and press the letter A.



This will highlight the whole track.



Now we have to go back to Noise reduction... in Effect ...



... and this time, when the box appears, do Step 2.  Click OK this time.



Looking at the waveform, there is less of that noise now than what we had at the beginning.



Below is a short DEMO for you to listen to.  First, you hear a bit of Denn's track 'as is' (with the NOISE); and then what it sounds like after our efforts to remove the NOISE.

NOISE REDUCTION DEMO

And here below is the whole track so you can compare this 'adjusted' version with the original.

Just Out Of Reach with the NOISE removed

What do you reckon?  Have we taken the NOISE REDUCTION too far and somehow compromised the music?

Hugh

Edit (by Hugh): Images are now LINKED to a new 'cloud' storage.  Text has not been edited.

[PhineasT]

If you have a clean noise profile (all noise, no music) you need to apply it like spray paint. Do not try for a final result with one heavy application - use lighter percentages and repeat until "coverage" is adequate. Some parts of your recording will likely need more light applications than others. And keep in mind that the listener's brain will naturally filter out noise if it is reduced to a low enough percentage of loudness, so you likely do not need 100% elimination. You may hear it because you are tuned in listening for it, but the normal listener may not hear it at all.