Audio Dodo needs help please

Hi there


I don’t quite understand this audio stuff
I have done an audio book and attempted to put it through acx and keep getting it knocked back because of this

The following files either have noise floors with high buzzing or other noise issues, or damage and artifacts due to noise reduction

I tried to follow instructions, noise removal, compression etc but this has been going on for quite some time and I dont understand how to check or rectify this,
I made the recordings in audacity, exported to WAV and make MP3 with freac as instructed. I cant hear anything wrong, but then again I am an old fart so cant hear so well aparantly.
Can anyone please give me some advice (in simple terms, remember, old fart) how to find out what’s wrong and tell me how to fix this.
attached 10 seconds

Thanks a lot

Please post which Audacity you have - all three numbers - which Windows, and can you post that 9-second segment again as raw microphone performance before you processed it? Don’t help it at all, no effects, no filtering and no reduction. Don’t do anything to “help us hear it.”

If you don’t have the performance file before you processed it, then that’s the first mistake. You can dig yourself a hole very quickly by bouncing in and out of ACX conformance testing (as you’re finding).

ACX AudioBook performance specs are similar to broadcast, they’re pretty serious, and it’s not unusual for people to make their broom closet into a mini-recording studio to get around noise and echo problems. Do you have a Yeti microphone? They can have their own problems.

I like the voice. Now we just have to get it in a form that the ACX Quality Control robot likes. A human may have writen the notes to you, but you failed automated testing. Flynwill has written a similar testing tool for Audacity, so you can do home testing and avoid the ACX ping-pong match.

As we go.


I can recommend a correction suite of tools and settings, but I can only do that after you post the “clean” sample. That will also tell us what you sound like without all the corrections and distortions.

Chapter 2.wav actually does pass the technical standards, but you did some messy things to your voice to get there and that’s the specific complaint. I can’t prove this, but I strongly suspect after you miss the first couple of tests, you fall into a list of those requiring extra scrutiny.

I’ll get the tools lined up and ready to post.

I wrote a thing about how to use the standard Audacity tools to test your submission.

Start there and I’ll round up the automated process.

You have to pass three standards: Peak (overload), RMS (loudness) and Noise. Producing a modest volume, noisy home recording can be a death spiral because you fix loudness and that makes the noise worse. Then you fix noise and that gargles up your voice and messes with the peaks, etc.

Can’t wait for that clean test clip. If you need to create a new clip for testing and posting, I wrote a recording formula:

As we go.


One more. Audacity 2.1.0 is required for some of these tools to work. There were some recent improvements in the tools and filters and the older ones just don’t work very well any more.


OK. Here we go. I scrambled my tools and references and lost my continuity. I just hate it when that happens.

Attached is a picture of the automated test and a copy of the v1.3 analysis tool acx-check.ny. It’s a Nyquist type program.

Copy that filter into the Audacity Plugins folder. Restart Audacity.

Open the show and select the whole thing by clicking just above MUTE. Analyze > ACX Check.

That will only tell you the technical standards, not theatrical. You can produce a show with terrible sounding audio and still pass ACX Check. If you fail submission enough times, I suspect they start testing for both.

Screen Shot 2015-06-26 at 11.53.31.png
acx-check.ny (5.6 KB)

It sounds like you’ve used a noise-gate , but it’s settings are chopping-off the ends of words.
Solution: increase the release-time, ( aka decay time ), of the gate, and/or increase the threshold of the gate, so that ends of words are not lost.

The word “village” has overload-distortion : distorted because it’s too-loud , ( not fixable in post production ).
Solution: move further back from the mic , ( any reverb from the walls of the room will become more obvious when you do that ).

IMO sibilant sounds are too loud : it needs de-essing . If you’re using a Windows computer a free de-esser plugin is “Spitfish”.

Thanks Koz
I understood some of your great advice. I use Audacity 2.0…6 and Windows 7. I saved as I went along I am afraid, so didnt keep original I have done a test sample as per instructions. I am using a different microphone my other one gave up, due to my stompimg on it
I downloaded and opened this acx-check.ny but it came up not recognised file. Do I do something else with it first.
Thanks a lot for the help and hope you can help me sort out this headache.
Thanks Trebor
How do I do this Solution: increase the release-time, ( aka decay time ), of the gate, and/or increase the threshold of the gate, so that ends of words are not lost.

It’s a Nyquist file and I think I’m going to start sending it out as a Zip rather than the raw file. Some systems convert it to acx-check.ny.txt and then Windows hides the .txt part making you think you have something you don’t.

You shouldn’t be using a noise gate at all. Those are very difficult to make sound natural. The object of recording is to simulate somebody sitting across from you over cups of hot tea telling you a story.

Overprocessing is a frequent ACX complaint when people try to fix bad recording techniques with post production effects and tricks.

This is a slide from one of the ACX publications.

I need to get to a computer with a good sound system and have a good listen.


You don’t “open” the file. The file needs to be copied into the “plugins” folder of your Audacity installation. Under windows this is usually (but not always) “C:\Program Files (x86)\Audacity\Plug-Ins”. Detailed instructions are here: Missing features - Audacity Support

I’ve never encountered files getting renamed to “.txt” on download but if that happened then yes you’ll need to fix that as well.

If you’re going to use the noise-gate, my suggested settings for the Noise-Gate are highlighted in Yellow on the image attached to this post , ( you’ll have to click on the image to see it ) , those settings don’t chop-off the ends of words.

You can get the de-clicker plugin here … Updated De-Clicker and new De-esser for speech
and the Limiter plugin here … Missing features - Audacity Support

PS I don’t know about “ACX” criteria : the plugin settings shown are just to my personal taste.

PPS I forgot to add de-essing. Paul-L who made the DeClicker also made a DeEsser plugin , but the SpitFish DeEsser plugin I mentioned previously in this thread is less complicated and easier to use for the novice. There are YouTube videos on how to use SpitFish in Audacity, e.g. …

Old Fossil

I prefer “voice with character.” I think I could listen to a story in that voice. Let me make a cuppa…

“Did I ever tell you about the time your aunt Minnie and I decided to liberate a pumpkin from Old Man O’Brians pumpkin patch one Hallowe’en? It was a dark and stormy night…”

In an effort to make this as complicated as possible, do you have any way to post a longer clip? The forum will only allow you to post 10-20 seconds, so that’s good for testing, but not longer analysis.

My email poops out at 20MB which works out to be about 200 seconds. Anything longer? Many people use file posting services like DropBox.

I got the clip to pass ACX compliance without too much pain (attached - see last sentence) and I’ll post how I did it, but if you listen very closely, you can hear the echoes of your room. You’re clearly presenting from your office, kitchen or other room with bare floor and/or walls. If that’s your thing, then we can go with it, but there is a tiny risk ACX quality control is going to have words about it. I don’t know. Now you’re in their QC “Shadow Zone.” There’s no button to kill echoes and you can’t buy your way out with expensive microphones.

Your microphone does have an odd, soft buzz, but it’s not severe and I got it down far enough with gentle noise reduction. Please note you still sound human complete with “body noises” and you do not have chopped off words and cut phrases typical of a noise gate. Some presenters freak out when they hear themselves the same way others hear them, but unless their audience runs away with their hands over their ears, it is what it is.

I’ll post how I did it when I get back into the house. No exotic tools.


Screen Shot 2015-06-28 at 14.45.36.png

Sounds smoother after Paul-L’s De-clicker …

If only 4 bands are selected on Paul-L’s De-clicker the audio is processed in about half the playback-time.

Sounds smoother after Paul-L’s De-clicker …

Wouldn’t surprise me. I’m not processing for theater awards, just to keep the ACX Robot asleep.

Drag-select between .5 and 1.5 seconds.
Effect > Noise Reduction Profile.
It’s stunningly important to get a “clean” profile. Room and microphone only. No body, breath, or mouth noises. But you have to be there.

Select the whole clip by clicking just above MUTE.
Effect > Noise Reduction: 12, 6, 6 > OK.
This is the frying sound of your microphone. “Normal” is the compression of the beast: 6, 6, 6, but you need a little more help with that microphone.

Effect > Amplify > OK (don’t change any settings).
This step sets you up for the compressor.

Effect > Compressor: -20, -50, 3:1, .2 sec, 1 sec. > OK
This step increases the density or energy of your voice, but pushes the overall volume down a bit.

Effect > Normalize: [X]Remove DC, [X]Normalize to -3.2 > OK
Brings the overall volume up (hopefully to spec) and puts the blue wave peaks in the right place (-3.2).

Did you get straightened out how to apply the testing tool? You should get slightly better numbers than the first test. I increased the overall loudness a little.

Then run the de-clicker if you think it sounds better. This is where you find out the quality of your speaker or headphone system. If you can’t hear what you’re doing perfectly, this could be a very difficult journey. There is no “Pleasant Sound Button,” or “Run this analysis tool to see if you sound pleasant.”

At the end of the day, you need to listen to it and decide you like it. If you’re half-way good, the next test will be between you and the rights-holder.

Oh, right. The echoes. People have converted their broom closet to a studio and filled it with acoustic foam. I’ve been known to prop up furniture moving blankets to help cut down echoes and noise.

That only shows one of the two blankets.

That looks like a simple shoot, but that’s a completely soundproofed conference room.

Obviously, it would be cool to get rid of that microphone frying, but we can live with that.


Thanks everyone
Still fllumed though. I hope you can help Koz when you have a listen/
I didnt know I had used a noise gate. I dont know what one is. I just followed advice from the web and Ytube tube that said Equilise Compress and normalise. I just used the setting already on there. I also used the de clicker which you mentioned Trebor.
I wish I had seen the advice about mastering - what to avoid sooner. I am very green when it comes to computer stuff. I did get the ACX checker working (well my mate did, he said it was simple and It was…For him)
I hope you can help me fix the errors in audiobook and pass ACX check as it is 60 chapters long and I dont fancy doing it over it took me months to do
Thanks again

I hope you can help me fix the errors in audiobook and pass ACX check as it is 60 chapters long and I dont fancy doing it over it took me months to do

There’s no way to warn people not to do that and it happens all the time.

Do you have the raw, unprocessed chapter readings? In other words do you have show readings in the same form as the last short test you sent us—no processing?

A very common mistake is to save new work on top of old work instead of making whole new corrected sound files. That wipes out the original shoot. The first time you use an active processor like Compression or Noise Reduction, you’re stuck because you can’t easily take those effects out of the show later. If ACX rejects you, that could be the end of the world. There is no recovery from “Overprocessed.”

Production in Audacity Projects instead of sound files is not going to help you because Projects will not save UNDO. Once you save a Project and close Audacity, you can’t go back any more.

So was the last pass through ACX the “overprocessed” complaint? All 60 chapters? Do you have the original shoot sound files?


I didnt know I had used a noise gate

Because of the correction damage you submitted, it sounded like you had used a Noise Gate.

We can’t see what you’re doing. We can only go by what the clips sound like and historical knowledge of what the effects do. That’s the kind of sound quality that ACX was complaining about. Yes, you may have achieved ACX technical compliance, but you damaged the sound quality to get there.

It’s not that unusual.


I know you’re hoping to just snap to and wrap this up, but the current longest message thread on the forum, 39 chapters and over a year is Ian who just wanted to record his voice for an audiobook in an apartment in Hollywood. It worked, too. He’s a paid presenter now.

The previous champ was Bruno who just wanted to record his Flamenco acoustic guitar in an apartment somewhere in Portugal. I don’t remember how many chapters that went. I can look it up if you want…

In both cases they were trying to produce paid-quality work, not “Home Recording.” That can be a challenge.


Thanks again Koz and Trebor

I did not keep original before I tinkered
Some chapters passed ( attached file) but I dont understand why passed or failed
Would it be worth sending a full chapter that failed and see if you can tell me how to fix?

I asked way up at the beginning if there was a way for you to send us, or make available longer sound files. The forum doesn’t support that and email attachments won’t do it. That may be helpful and please include any comments ACX made in association with the work so we’re not flying blind.


Thanks Koz
I wonder if there is any way to send a full chapter. a mate suggested a dropbox?
I have copied, pasted and attached all the emails sent by ACX. I hope that may help.
I am not sure if the doc file is attaching I keep getting choose file and when I press add file it goes back to choose file.