Waveforms Disappear After Noise Reduction

[desdichado]

I am using Windows 10 Pro and Audacity 2.1.3.

I am recording a script for a YouTube video. Basically I’m just reading from a plaintext file while recording with my Samson Meteor mic. It’s a real ghetto setup, as I don’t have a stand for it yet. I just set it on its little tripod thingy on my laptop as I read from my screen.

Anyway, I managed to successfully record around 25 minutes of audio and everything appeared to be fine. The waveforms showed up as normal and I could play back normally. Then I sampled around eight seconds of noise from the start of the recording, which included a mouse click and some breathing, and ran noise reduction on the entire recording. I changed the level of noise reduction upwards from the default until it sounded okay in the previews, to 28 dB, 14 Sensitivity, and 7 frequency smoothing. Then I ran it, it took a few minutes. Afterwards, it had reduced the noise, and I could still play the recording back, but the waveforms had disappeared entirely. I checked at every level of zoom, and they’re just…gone. Understandably, this makes it very difficult to try to edit the recording, since I have no visual frame of reference. I tried undoing the noise reduction - the operation completed successfully and I was able to undo/redo back and forth, but while the recording itself was fine, the waveforms did not return.

I’d appreciate it if anyone who has encountered this issue could give me some advice, as I am a novice not only at using audio recording software, but at using pretty much any professional-grade software at all. Thanks for your time.

[desdichado]

I should add, as an update, that I just exported the recording as a .wav, closed out of the recording, then opened the .wav file, and now the waveforms have returned! While I suppose this “solves” my problem, I would still appreciate any feedback you folks might have as to why this error occurred in the first place.

[kozikowski]

It’s a real ghetto setup

Doesn’t bother me. I once shot the backing track for a television commercial on my laptop. No microphone, just the laptop.

which included a mouse click and some breathing

Audacity Noise Reduction works best on noises that don’t change. Air conditioning, computer fans, refrigerators, etc. Not so good on constantly changing noises. A good way to kill your recording is leave a TV on in the next room. No way to get rid of that.

If the problem is one mouse click, you can zoom into the click and surgically remove it with regular editing tools. Breathing is more of a problem. If you’re asthmatic and constantly gasping for air, maybe you shouldn’t be reading out loud.That’s going to be very difficult to fix.

28 dB, 14 Sensitivity, and 7 frequency smoothing.

That’s very stiff, hard removal. The highest removal recommended for AudioBooks is 12.6.6. More like 9.6.6. Higher than that and your voice is going to start acting funny like talking into a wine glass.

Before you mess with it any more, select the whole clean, unfiltered reading and File > Export: WAV (Microsoft) 16-bit. Copy that somewhere like a thumb drive or backup disk. This is your protective backup and it’s good practice for later. If you’re in the middle of editing a chapter of your audiobook and the computer goes up in a ball of flame, you will not have to read the work again.

If you have no clean work, Edit > UNDO what you have until you get back to your original reading and Export that. If you turned the computer off between the reading and now, there is no UNDO.

You can get your noise reduced show up by brute force with Effect > Amplify > OK. If the top number, amplification, is higher than about 30dB, then I think the show is unrecoverable even if it does get louder.

Read something according to this recipe (it’s 20 seconds) and post it here.

http://www.kozco.com/tech/audacity/TestClip/Record_A_Clip.html

You can’t post a book chapter. The forum will only accept short clips.

Koz

[kozikowski]

I should add, as an update,

Dueling posts.

No, having the blue waves vanish is not normal. When was the last time you clean restarted your Windows machine? Shift-Shutdown and just wait it out. Then restart. It will take much longer than normal, but more likely to start clean.

Koz

[desdichado]

When was the last time you clean restarted your Windows machine?

Not that long ago, but I did as you said, just to be safe.

If you’re asthmatic and constantly gasping for air, maybe you shouldn’t be reading out loud.

Not an asthmatic, but like anyone who’s never done voice recording before, I do make more breathing noises than I’d like in-between “takes”, and sometimes while speaking. It’s not a serious issue on the recording itself, I just mentioned it to be thorough. Perhaps I shouldn’t have sampled it as part of the noise signature, just as I shouldn’t have done so with the click?

The highest removal recommended for AudioBooks is 12.6.6. More like 9.6.6.

Roger that. I figured it might have been too high, but like I said, I’m new to all this. Of course, you’re not saying that that is what killed the waveforms, are you?

Before you mess with it any more

Oops! Too late. Like I said in my previous post, I exported it with the noise removal as a 16-bit .wav. Ah well. It wasn’t a great recording anyway, to be honest. I can just try again. I’m a NEET, so my time isn’t exactly priceless.

You can get your noise reduced show up by brute force with Effect > Amplify > OK. If the top number, amplification, is higher than about 30dB, then I think the show is unrecoverable even if it does get louder.

By that, do you mean that if I think the noise removal at around 9.6.6 settings is still too noisy, I can just amplify the effect? I’ll try to remember that.

Read something according to this recipe (it’s 20 seconds) and post it here.

If that will help you help me, gimme a minute and I’ll attempt that for you.

[desdichado]

Here’s the audio test you asked for.

[kozikowski]

It’s not unusual for a New User to go off the deep end when all they needed was a little volume change here and there. I’ll listen in a minute. We had a recent poster who, after we got them to record reasonable volume in their studio, was able to pass AudioBook quality standards (barely) with minimal corrections and processing.

As we go.

Koz

[kozikowski]

I changed my mind. You should probably go off the deep end.

That explains the high noise reduction numbers. The background noise in your system is stunningly high. I can’t get you to a clean reading no matter what I do.

Describe your microphone and room. I hear “bathroom” echoes. Does your recording room have fashionable bare-wood floors and plain white walls? You don’t need fancy-pants microphones, interfaces, mixers, etc, but you do have to be careful how you record.

Do you have an iPhone or later model iPod?

Koz

[desdichado]

I changed my mind. You should probably go off the deep end.

Sounds fun

The background noise in your system is stunningly high. I can’t get you to a clean reading no matter what I do.

Weird. The only thing I can think of that would cause that is my laptop fan, and it wasn’t working particularly hard during the recording.

Describe your microphone and room.

Like I mentioned, I’m using a Samson Meteor usb mic, jacked into an old Lenovo ThinkPad W520 model laptop. My headphones are plugged into the mic itself. The whole setup is sitting about a meter off the ground on an old hardwood office desk, which is cluttered with speakers and a set of wooden box-shelves. I’m in a small bedroom with carpeted floors, though it does have bare white walls. My bedroom door was open during the recording…perhaps that effected things? You mentioned a “bathroom” echo - my bedroom door opens onto a short hallway, with two rooms with open doors right next to it, one of which is a bathroom.

I don not own an iPhone or any other iDevice.

[desdichado]

Apologies for what will probably show up as dueling posts again, but I think I might know at least part of the problem. The Meteor mic has an integrated tripod made of solid metal. I noticed when playing around with it that it would pick up even the slightest vibration in its “legs” while recording up into its frame. What I didn’t think of was that setting it on top of my laptop would allow it to pick up the internal vibrations from the laptop fan. Do you think that might be it? Dammit, I really do need a stand for this thing.

[kozikowski]

According to the microphone instructions, you should be speaking into the side opposite the headphone socket. The headphone plugs into the back.

The microphone is a cardioid type (heart or kidney pattern) and has a sound dead spot directly in back. This is a rock band microphone with the same pattern.

Any chance of putting the laptop back there, in that notch or hole?

Here’s some soundproofing tricks.

It doesn’t have to be Stephen King. Any heavy book will do it. Please note I have the desk covered with a heavy blue furniture moving blanket. Any blanket will do, the heavier the better.

If we can get rid of about half the noises, I may be able to push you the rest of the way into a clean recording with effects and filters.

Koz

[kozikowski]

I really do need a stand for this thing.

Or a good book.

You don’t need multi-thousand dollar microphones. You just need to be careful with what you got.

Koz

[desdichado]

you should be speaking into the side opposite the headphone socket

Well, I knew that much…

Any chance of putting the laptop back there, in that notch or hole?

By which you mean, the laptop should be as far behind in the dead spot of the microphone as possible (behind and underneath)? I think I could jury-rig something along those lines, sure.

I have the desk covered with a heavy blue furniture moving blanket. Any blanket will do, the heavier the better.

Would simply covering the desk itself in a blanket be enough, you think? I can certainly manage that much, and put the mic on either a book or perhaps a piece of furniture next to me and in front of the laptop. It’d suck if that was still too noisy, though. I’m not sure how I could securely attach a bunch of blankets to the walls of my apartment.

You don’t need multi-thousand dollar microphones

Sure, but it’s still kind of awkward to try to speak into this mic closely enough without grabbing it, especially when I’m also trying to read from a script on the laptop screen. Anyway, I think I’ll take your advice, work out a new setup, and then take a new sample for you. Might take a bit, but I’ll post it here when I’m finished. Thanks for your help so far.

[desdichado]

Okay, so…

I attempted to re-arrange my room a number of ways, some involving blanket forts, but eventually decided I was over-thinking it and just set my mic up inside of the box shelf on my desk. I made a little nest in there of old sweatpants that covers both the bottom, sides, and top of the small enclosed space. When I wanted to record, I just hit the button and then read from a teleprompter program I found. Thus, the mic is at about standing height in a little soft absorbent “booth” to the right of my laptop (the laptop itself a little lower than waist-height on the desk), and I can read from the screen and speak into the mic at the same time.

I recorded a sample for you. Here it is. Let me know what else I can do to get the noise within acceptable levels.

[kozikowski]

Well, I knew that much…

You’d be surprised how common it is to find people speaking into the end of the cylinder like a rock-band microphone instead of the side. We have a pretty good idea what the front and back of the microphone sound like, but the top is undefined territory.

(behind and underneath)

Straight back should be enough. There’s nothing surgical about the dead area behind. It changes with the pitch of the fan whine, too, so just get close.

I’m also trying to read from a script on the laptop screen.

Inexpensive microphone stands are the answer.

That’s not for show. I shot a test clip like that a bit ago.

I gotta drop out for a minute.

Koz

[kozikowski]

Do you know where the microphone on your laptop is? Mine is behind a grill just to the left of the left-hand shift key. The laptop before this one was actually on the lid behind a little hole.

Something Is Very Wrong.

Let’s do a scratch test. Start recording and say “this is the microphone” and scratch the Meteor grill with your finger. Then say “This is the laptop” and scratch wherever it is on your machine.

http://kozco.com/tech/audacity/clips/ScratchTest2.mp3

Koz

[desdichado]

Do you know where the microphone on your laptop is?

No, but I can find out easily enough.

Something Is Very Wrong.

That’s…disconcerting.

Gimme a few minutes and I’ll find the laptop mic and attempt a scratch test. I assume you’re thinking the laptop mic is on at the same time as my Meteor? Or something?

Anyway, be back in a bit.

[desdichado]

Here’s the scratch test. FWIW, it didn’t sound to me like my laptop mic was recording.

[kozikowski]

How far away from the microphone are you during performance? You should be somewhere between Power Fist and Hawaiian Shaka (attached).

Your first voice during the scratch test is almost perfect. Your voice during the test clip performance is very low which almost without question is causing the noise problems.

Koz

[kozikowski]

This is our friend David Greene with two different microphones and about the right spacing for both. He’s using pop and blast filters for both because when you get closer, you have a risk of popping your P sounds. I can’t find it immediately, but somewhere here is a suggestion document how to pile up books and household items to get your microphone closer to your lips. Everyone will gasp in horror, but you don’t have to speak directly into the microphone. You can have it half-way off your left cheek which can help boost volume and is less likely to pop your Ps. You can’t go too far to the side because that will start sounding muffled.

Koz