How to remove ambient noise?

Hello guys,

I’ve read through threads after threads and watched videos on YouTube regarding the removal of the static/ambient noise of my recorded piano track, but to no avail. I used an app called Voice Record on my iPhone 5 to record the piano piece as I played. I’m wondering what are the precise numbers I must put in to the filters in the Noise Removal tab in order to remove the sound. I managed to remove the static sound, but the track ended up being distorted with shuffling sounds popping in sporadically. =/

Below, I’ve attached a sample of the track I’m currently editing.

Please help me…and much appreciated!
sample.aup (5.42 KB)

AUP is not a sound file. It’s a text file and performs Audacity Project Management.

If you do post something, post it high quality before you messed with it.

Most posts that start “Can you clean up…” (even though yours didn’t) probably need to shoot the show again paying attention to good recording techniques. Clean recording is harder than it looks.

Noise removal works in two steps. The profile step where you let the filter “taste” the noise by itself with no performance at all. Once the profile or noise sample has been established, then run the tool again and it tries to remove that taste (profile) from the show.

It rarely works the way everybody wants it to. We can’t remove “rain in the trees” white noise for one example. We probably can’t remove static for the same reason. The tool tries to remove too much of the show giving you martian voices or underwater bubbling.

Noise Removal does have one slider that tries to help with this problem. The “Smoothing” setting allows Audacity to remove noise everywhere except spoken words. If you luck out, this is enough to get your through. If not, then you will get hissy or noisy words over velvet quiet.

This doesn’t work at all for music.

One trick is to use the minimum needed removal (first number) like 6, 9, or 12. People try to get dead silence in the first pass and that never works, but sometimes you can get half the amount of noise without breaking anything else and that’s good enough.

When you post your sample, we should be able to tell you how to reshoot it.


Hi Koz,

I’ve just attached a five second sample of the track. I messed with all of the filter settings and Frequency Smoothing does yield a better result, but if set too high then the sound would decay very rapidly, if set too low there would be shuffling sound.

Thank you for your quick feedback!

Drag-select the flat, noisy area to the left of the first note. Do not include the little ticks on both ends. Effect > Noise Removal > Get Profile.

Select the whole song and apply Noise Removal with the illustrated settings.

Screen shot 2013-09-17 at 12.23.07 AM.png

That’s all microphone white noise caused by you not being loud enough, or having the microphone (phone) too far from the performance. This will be sticky because the music sounds OK. So you may fix one thing and lose something else.

If this is a real piano, can you put the phone just inside the lid.

Also, because it’s a phone, it might easily be trying to perform automatic volume on the show. Maybe not. Consult your directions. If the noise comes and goes, it’s going to be particularly difficult to remove.

Screen shot 2013-09-17 at 12.30.56 AM.png

Holy Koz…you’re a miracle worker! >.<

How did you resolve the issue so quickly when it took me hours and still couldn’t arrive to the solution?! The setting you illustrated worked perfectly!

Actually, I record my playing on a electric keyboard (because my keyboard click-clacks a lot!) then record the piece with my iPhone 5 hovering just above the equipment. I will definitely turn the volume up when I record next time, but if I may ask, wouldn’t the sound pop if it’s too loud or when the sound is in the very high register?

Thanks for your help! :3

How did you resolve the issue so quickly when it took me hours and still couldn’t arrive to the solution?! The setting you illustrated worked perfectly!

We’ve been doing this a long time. You have to have a feel for what the sliders do and it’s not simple.

wouldn’t the sound pop if it’s too loud or when the sound is in the very high register?

Yes, absolutely…if it was a regular microphone and recorder. Many things in a live microphone system can create overload problems, but I’m betting you’re never going to have those problems because your noise is typical of a system gasping for air because it doesn’t have enough volume.

The sound recorder on my iPod has a little sound meter.

Didn’t your recorder come with directions?


Sure thing. I’ll try recording with the louder volume.

My recorder also has a meter, but it lacked any instructions. It’s basically ranged from -20 to 3+ VU. I tried to keep the volume between 5 and 3.

Thanks for the tip, Koz!

That’s normal for a recording system. I wonder if there isn’t something else wrong. This instructional video is clear and doesn’t seem to have any noise problems.



This thread can now officially be closed and I hope other people could find meaning in it.

Thank you Kozikowski for your guidance over these past few days. I owe you one!


And because Koz is a consummate professional :slight_smile:

And a pretty good problem-solver to boot …