How do I remove background noise in my audio?

Hi, there! :wave:

According to ACX, I have some background noise in my files, but I don’t hear what they’re talking about. What do you suggest I do to correct this?

How do I go about getting rid of the noise only?

That’s good because if the noise isn’t bad you might be close to passing. :wink: They are (obviously) measuring the quiet-parts when there is no talking… They aren’t listening.

If you don’t have it already ACX Check, will check your peak, RMS, and noise levels.

Koz’ Audiobook Mastering Macro will set the peak and RMS levels (and won’t hurt anything if they are already good), plus it includes a high-pass filter to filter-out any low-frequency noise (below the voice frequency range). The worst measuring noise is often in the lower frequencies where it is harder to hear, but they’ll still measure it.

If it still doesn’t pass you can try Noise Reduction which requires you to feed-in a Noise Profile (A sample of noise only).

Can you post their exact comment?

Also, select 10-11 seconds of the show, export it as WAV (Microsoft) and post it on the forum. The upload icon is the heavy bar with the up arrow.

Depending on the kind of nose, this problem could be pretty serious.

Koz

Thanks, again! Have a great day! :grinning:

Hi Kozikowski,

Issue: The files submitted for this title contain excessive background/ambient noise and do not meet our noise floor requirement: all files

Requirement: a maximum -60dB noise floor

Solution: In post-production, you may use noise gating or reduction to help reduce the noise floor. Please be mindful that incorrect use of this kind of software can lead to poor sounding audio. The best way to go about lowering your noise floor is to identify and eliminate the source of the noise. Often it could be the microphone picking up a loud sound from within the room, or it could be a gain staging Issue with your recording equipment. Please be sure that any noise-emanating appliances (air conditioner, computer fan, fluorescent lights, refrigerator, etc.) are turned off or isolated so the microphone does not pick up those sounds. The Mastering topic in our Video Lessons & Resource section contains samples of what a good noise floor should sound like.

Cool. Now post some of the work and we can (usually) tell you how to get rid of the noise.

It’s all spoken word, right? Make sure there is at least one natural pause or space in the sample [pause]. Like when you take a breath at the end of a sentence.

Do Not specially edit a blank space into the piece you post. We need the space to have the natural room or environment sound.

What format are all your chapters in? Like if you point to your chapter edit master files, are they all MP3 files, aup3 files, or something else.

Koz

Okay, will do. Yes, I also included sound effects in some of the chapters and some are spoken word. My chapters are MP3 files.

Okay, will do. Yes, I also have sound effects in some of the chapters and some are spoken word. My chapters are MP3 files. I attached an image because someone said that it could be the noise when it’s not the talking parts.

Koz,

I’ll post some of my work, but will everyone be able to hear it or will it go directly to you only? I perfer only you. :grinning:

I think you can click on the blue “K” in the ball. That should give you the forum messaging connection. The upload icon is still the bar with up arrow.

Post here on the open forum when you post the private message. I don’t get the notices.

Traditionally, ACX didn’t much like Radio Theater. The best you could do is brief introduction music and then spoken word for the rest of the chapter. They may have changed that.

There is one really bad news item. I strongly recommend producing your Edit Master Chapter files as WAV (Microsoft) and not MP3 or aup3 files. Audacity aup3 files, while containing perfect sound, can be brittle and easily broken; and you can’t edit an MP3 file.

What?

You may remember from the ACX instructions that MP3 submission quality must be Constant Bitrate at 192 (or higher). If, for example, you have to apply a simple noise reduction to your chapter, You would think you would just File > Export the clean chapter as MP3 192 again, right? No actually. You can’t 192 compress a 192 MP3 file. The new file will be at a lower compression quality and you can’t stop it.

I’m pretty sure you can’t submit it that way.

One of the tricks that MP3 uses to get its small, convenient sound files is look for really quiet sounds in the performance and throws them away. This is based on the idea that nobody is going to miss them anyway. If you make an MP3 from an MP3, it does it again.

Before I get all Debby Downer, let’s see what’s wrong with the chapter.

Koz

It’s possible the sound effects are what ACX doesn’t like. Again, traditional audiobooks (if you bought any) consist of the announcer introducing the work and then talking in a pleasant, entertaining manner for a chapter. Repeat.

No music.

This is a sample of “Assassination Vacation” by Sara Vowell.

Koz

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This may also introduce you to another ACX oddity. They won’t chat with you.

“This is what’s wrong with your submission. Have a happy day.”

Koz

Okay, gotcha. :wink: I’ll send through the arrow on the messaging forum connection. ACX didn’t mention anything about the sound effect, so that’s a good thing, right? You’re saying edit all the chapters as WAV (Microsoft). Of course, I don’t have a lot of knowledge about this and I know you do. I’ll send my work over to you in WAV (Microsoft). So before I resubmit to ACX will it be in their requirement of 192? Hopefully, I won’t have any problems. I’m a little confused on all the technicals, but I know you know your stuff and I really appreciate you!

Try OpenVINO in Audacity, it’s pefect.

Thanks! I’m not an expert, so I’m absolutely cluess to what this means. LOL At this point, I’m looking and willing to pay someone to assist me with finishing up my project.

I’ll need to get back to this when it’s not 01:00.

Koz

I decided to rerecord it with a better quality mic. :grinning:

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Depending on where the noise is coming from that may, or may-not, help.
A directional mic helps with acoustic noise because noise that’s not coming from the front is reduced.

Condenser mics have about 20dB higher output than dynamic mics. That gives a better signal-to-noise ratio relative to any preamp noise. But it doesn’t make any difference with acoustic noise because the signal and noise are changed by the same amount.

…It’s acoustic noise that makes the biggest difference between home recording and a soundproof pro studio. And sometimes USB powered interfaces get noise into their preamps from the USB power (which tends to be noisy).

There’s different noises, too. Normal microphone noise is spring rain in the trees SHSHSH or FFFFF. That’s the microphone system. When you record on the computer there’s a whole festival of different kinds of noises. A famous one is screaming mosquitoes. That’s when the USB housekeeping leaks into the voice.

That will not conform to the -60dB sound specification. That’s not gentle rain. That one is more like baby screaming on a jet. You can pass ACX-Check and still fail noise with that one.

If you do post some sound on my account, also post a note about it here on the open forum.

Koz

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