Noise Floor Frustration


After I’ve done filter curve EQ, loudness normalization and limiter, I will ACX check. Usually at this point, my peak level and RMS pass and my noise floor fails, which I expect.

Then I will apply a noise reduction to the entire file. BUT I usually still have mouth noises throughout the track.

So naturally I go through and try to remove all the noises.

In some cases, if I simply edit out a piece of track, all of sudden my noise floor is too low (-dB dead silence).
In other cases, if I paste room noise over a mouth noise, again, all of a sudden my noise floor is too low (-dB dead silence).

As I’m sure you all can imagine, this is extremely frustrating, as I feel like I am trying multiple ways to get rid of the mouth noises and keep hitting a wall whichever way I go.

What do you experts recommend? What has worked for you?

I record on a Yeti hooked into my computer via USB and I record directly onto Audacity. I’m not looking to invest a lot of money into equipment because I am a beginner and I haven’t made that much money yet.

Thank you in advance.

PS I have no formal audacity training outside of “YouTube University”

Then I will apply a noise reduction to the entire file. BUT I usually still have mouth noises throughout the track.

What are your noise reduction settings? If you need powerful noise reduction, that may reduce the noise but boost the tongue ticks, lip smacks, and other mouth noises.

Rather than ping-pong back and forth across the forum, record a ten second voice test using your normal technique and post it here.

Read down the blue links. They’re very short. Do Not apply any corrections to the file.

I will ACX check.

If your goal is ACX Publication, there are a couple of non-sound notes. I must be able to buy your book on Amazon. Full Stop. They won’t let you do this out of order. Your book must not be on this list (scroll down). You can’t publish a cookbook.

I suggest your book must have plot, characters, and setting. There are odd variations. I really like the Hero’s Journey audiobook where Joseph Campbell discusses Plot, Characters, and Setting.

I have first-hand experience with mouth noises. That’s why my audiobook submission failed.

“Your sound file is perfect in every way, but your voice could use work.”


Thank you for your reply and the resources. I use the noise reduction settings as they come standard in Audacity. I have not altered them.

I have been able to improve my recordings with breathing and mouth techniques. I think this was a big part of my problem as well. I’ve also learned to use room tone to edit out some of my mistakes.

This is a learning process for sure!

I’ve also figured out that if I apply noise reduction after loudness normalization and before limiter, it doesn’t seem to affect my ACX check negatively.

I use the noise reduction settings as they come standard in Audacity.

You might want to alter them. The original Audacity recommendations had settings such as 6/1/3 or something like that. I found for gentle, graceful, and effective processing you can try “Noise Reduction of the Beast” 6, 6, 6. That noise reduction setting bumps the background noise level down without affecting the show quality and most importantly, ACX can’t tell what you did. If that’s not quite enough, you can bump the first number up as far as 12 before you start to introduce some sound distortion. Enough people found this to be useful that I understand the Audacity default has been changed to 6, 6, 6.

I found a trick for those of us plagued with mouth noises. Don’t put the microphone in front. You can use Oblique Positioning (B) and get good tonal quality, a bump up in volume, and greatly reduced ticks, clicks, and pops.


There’s another note, too. You should know that the three steps in Audiobook Mastering may look simple, but they depend on and clean up after each other. You should not change the order, add any tools, or leave any out.

I would probably do all the mouth noise patching before mastering, and then Noise Reduction of the Beast after—if you need it.

Filter Curve, step one in Mastering, gets rid of rumble, thumps, and other low pitch noises. It was designed after the wind filter sometimes used in outdoor performances and News Gathering. If you have a rumbly studio, this can do some pretty amazing things. It pre-conditions the voice for Loudness Normalization. Normalization, while it’s setting performance volume, has been known to create wave tip and peak problems and so the Limiter is used to bring those into alignment.

Please note that sound doesn’t overload inside Audacity. Audacity uses a special sound format that doesn’t distort if your blue waves go over 100%, even if you have those red clipping warning lines. The Limiter Peak setting is slightly quieter than required by ACX to make up possible problems converting from WAV to MP3 for audiobook submission.

When you complete your first pass performance, Export the work, accidents and all, as a WAV RAW recording. This is against your machine going into the dirt during editing and taking your show with it. Open up a copy of the raw recording and keep going.

When you get done with everything, Export your chapter as a WAV Archive Edit Master and only then make the MP3 for ACX. You can’t change an MP3 once you make it without creating sound damage.


Are you going to post that ten-second sound test?