Clicks Appearing When Pasting Ambient Room Sound

Sometimes we can think of additional odd tests and in rare instances, it turns out your file may not be broken at all.


definitely what I wouldn’t like to happen. When I get an example I will. The clicks themselves sound more like low-level bumps, but when files have been ACXed they are more prominent and bumps inbetween words don’t sound very professional.

Okay then, I’m doing my edit, I have a breath I want to remove, I punch paste over the breath between the words ‘patience’ and ‘discipline’. I have two clicks at the start and end of the paste.

Here’s the spectrogram:

Screen Shot 2020-06-14 at 20.09.06.PNG.jpg
Here’s the extracted .wav

Of course, after ACX treatment the hits are much more conspicuous. And that’s happening with maybe eight out of ten punch pastes. If I just delete audio, I get just one click of about the same level.

when files have been ACXed they are more prominent

Even more important to get a sample. The first step in Mastering is Low Rolloff that typically suppresses low pitch tones—thunder and trucks going by, but the next step typically increases overall volume. That’s the point where everything gets louder and you notice quiet tones more. It’s an oddity of the ear.

We’re on the edges of our seats.


I was fidding the post with the sample in it. There for your delectation.

The punch-paste tool has a cross-fade setting,
IMO it shouldn’t be less than 10ms, otherwise there may be a conspicuous click at the join.

Thank you, Trebor! Punch Paste was set to the default of 0ms and I was clearly getting a conspicuous click at the join! I changed that and haven’t had an issue since. Thank you so much, I’ve not been having the best few days trying to figure out what I was doing wrong. Even though it’s a simple thing, sometime you need another head when you’re in the middle of a panic.

Thanks again for your help Trebor.

Just a note we didn’t solve the problem. We just covered it up.

I’m curious how you found the damage. Even after mastering and processing, the pops are, by my measure some -66dB. which is quieter than the audiobook standards for background noise. If you hadn’t told me they were there, I would never have found them. And it’s a good chance that ACX isn’t going to find them, either.

It doesn’t count if you have to crank up the headphone or speaker volume to hear the damage. The rough idea is to settle on a normal listening volume for the show and then listen for the damage without touching anything.

The other thing you can try is produce a new background noise sample. If you have one bad noise track it will create odd, random problems forever. One goal is to produce good work with as few tools and corrections as possible. That’s the business side.

Glad you’re up and running.


I think I got it.

Your pasted noise sample isn’t clean.

The second click in your posted example starts out “grass” or pure noise (blue line) but then rises into a real sound (red line). At that exact instant you cut back to the performance which gives you a click or pop (green line).

This effect will change depending on how long the pasted noise is. That gives you the magic of sometimes it pops and sometimes it doesn’t.

The extra sound could be anything. You moved a little in your seat or started to take a breath while you recorded your noise sample.

I think if you re-recorded your background noise and are more careful about extra noises, all these problems will vanish without special tools or masking.

If you can hold your breath and freeze for 6 seconds, that should cover the 5 seconds that ACX suggests for the end of chapter room tone. Everything else should be shorter than that. If you need longer, paste twice.

Do you correct the breaths before or after mastering? Some microphone systems create their own noise while recording and it doesn’t matter what you do.


Really? I was thinking that ANY noise that isn’t silence would get noticed, when the human QC happened, you see. Perhaps I’ve been very(too?) fastidious when it comes to extraneous noise. I use the multi view to see both waveform and spectrograph. I see them on the speccy.

But that seems to make it much easier than I have been thinking it is! I mean when ACXed, those bumps sound like, well, louder bumps, but not like a crack or pop that I would call distracting. It’s just I can hear them and I then think other people, customers and QC will, you see?

That explains that then. I notice too that you’re looking at the audio in the db view, not waveform, I’m not doing that; I think I might be missing out on information.

I’m using a Rode NT1 kit with AI-1 interface I’m in a treated area but I am keeping the record level low, when not speaking level rarely gets above -60 on PCM monitoring as i read -57/60 is a good quiet value somewhere when I was getting set up, getting peaks at -20, -18 and bumping up +2db to edit if it seems quiet. I edit breaths as I go, before ACXing.

My ideal workflow is minimal manipulation of files as possible. Ideally I just want to record, edit breaths and timing and ACX it and that’s that. Maybe a NR pass but the mic and interface are quiet enough most times. And then I don’t know if it’s best to NR the fles before or after ACX chaining.

I think I may be concentrating on the DETAIL of the file too much. It’s not uncommon for me to fixate.

Thank you.

I would try an expander plugin (like Couture) first to squish down the noise-floor (~6dB) when you’re not speaking, before resorting to Noise-Reduction.

The free version of Couture is sufficient, (other expander plug-ins are available).

That does look fancy! I’ve installed it and I’ll give that a shot, I’ve clicked at some things but I really am only guessing that it’s something to do with the knob bottom left, the other controls just make me sound funny.

I assume the red track is the modified waveform vs. the original? I mean I meddled with the bottom left knob, dropping it to -6db and got this on the waveform, the silence seems lower and the speech looks as it did, so that’s good, isn’t it?

Screen Shot 2020-06-16 at 21.53.25.PNG
But I mean I get good numbers on ACX check anyway.
Screen Shot 2020-06-16 at 20.44.31.PNG
But it’s always good to get better.

…and that’s because noise reduction is destructive, whereas this just - as you say - squashes the quiet bits to be quieter? Still new to most of these principles, want to get my head around them. It looks like sitting down and flapping the gums isn’t enough.

Turning all the knobs to three o’clock & “x1” is what I usually have.
That’s enough to knock the noise-floor down by 6/7/8dB,
but not so much that it sounds gated.

You mentioned that the noise floor was close to the ACX requirement of -60dB,
which is why I suggested Couture to get it down another ~6dB.

That’s the idea, that the speech is largely unaffected, (there may be a bonus of slight reverb reduction)

alright then, I’ll mess about with the settings and see what I can do. Thank you for the steer. Looking at the original pic posted of your plugin, you have it set like that there! I should pay more attention to what I see.

of course; as that’s the highest noise loor value (as it were) that ACX accept. So lowering it is good. I get that now. But also lowering record level would do the same thing? No… it means the speech would be lower too. So where I record low and give a little +2db bump up, I can use Couture to push the quiet down further, so I could have record level a little higher to start, if I understand this right.

I’ll delve deeper into this, but the take aways are cleaner slience for patch pasting and lower the noise floor further with an expander instead of NR. And perhaps don’t be so fixated on every spike on the spectrograph.

that being said, I could also bump up low(er) level recordings and THEN squash the floor down too, couldn’t i?

I would get the RMS to the required level, (using RMS normalize),
then apply Couture if I needed to bring the noise-floor down, and/or, dry-up slight room-reverb.

so squeeze it in before limiting on the ACX chain, if needed. Thank you, I’ll have a play.

Just to throw to another thread before this one gets put to bed, I’ve found that Couture seems to crash Audacity, at leaast my install does. Not all the time, but some of the time. And I was poking around the boards investigating expanders and I happened across this in the Nyqust dev board about Chris’s compressor. Would this do the same thing as Couture if set to negative values then? What’s the difference between the two? Or perhaps, is an expander a backwards compressor?

Exactly: full names are dynamic-range-compression & dynamic-range-expansion.

Steve made a Nyquist Plugin called dynamic mirror which can expand,
but it’s not as good as Couture: it doesn’t allow different attack & release times,
& I think there’s a limit on how much it can process in one pass, (an hour ?).