audio editing

How to Fix a "P-Pop" in Your Audio With A Sound Editor

April 3, 2017 by Ken 6 Comments

Here is how to fix a p-pop in a recording using sound editing software. If you do any voice recording at all, you’ve probably noticed this. No matter how hard you try, your “P” sounds (called “plosives”) will sometimes sound like small explosions in the audio. These plosives sort of distort the audio recording for a second, sounding a bit like a low-frequency “splat.” Not pretty.

What causes it?

It’s what happens when a burst of wind hits a microphone. It’s especially pronounced when using a large diaphragm condenser mic like the one in the pic on the left – a Rode NT2-A. There are things you can do to minimize or prevent (shya!) them (like a pop filter), which is the best medicine. But when they do get recorded, you’ll want to know how to fix it after-the-fact. For this we use editing software. One of the wonderful things about audio editing in the computer age is that you get to use your eyes as well as your ears. I have edited so many p-pops (caused by what linguists call “plosives”) that I can recognize what they LOOK like on a computer screen even before I hear them. For my voice, the come out looking like a capital letter “N” in the waveform.

How to fix it once it is recorded?

Since the plosive problem is basically caused by a rush of air from your lips hitting a microphone capsule fast and hard, what you have is a problem of volume. The plosive was too loud compared to everything around it. Not only that, but most of the too-loud bits are in the low end…the bass frequencies. So the fix would be to turn down the volume of your voice when it is hitting the “P.” In an audio editor, like Audacity (which is open source) you zoom in on the plosive and select everything right up until the voice actually becomes audible. In other words, if the word was “pot,” try not to get any of the -“ah” sound in your selection. You only want the “P” sound. Then you just use a volume reduction tool to turn down JUST the “P.” You may have to experiment (“undo” is the magic-bullet of computer audio editing!) with how much you turn it down, but that may be all you need to do.

What if changing the volume doesn’t work?

If adjusting the volume doesn’t get you there, you might just need to reduce the volume of PART of the plosive, the bass part. You do this using equalization (EQ). That is basically the same thing as volume, only you control what frequencies get turned up or down. Try reducing volume of frequencies below 200 Hz and leave everything else alone. Again, you may need to experiment. Now you just lather, rinse, and repeat for every bothersome “P” pop, and you’re done. It’s so easy to fix that I am baffled that some voice-overs still have them. At least you don’t need to anymore. See the video below for a way to do this using Reaper software. The idea is exactly the same. But the method is slightly different because Reaper is a digital audio workstation (DAW) which edits its audio in a “non-destructive” way. Here is how to do this in Audacity [jwplayer mediaid=”17810″] And here is how to do it in Reaper Learn this technique and more audio editing in our video tutorials at Home Brew Audio!

Time needed: 5 minutes.

How to Fix a P-Pop in Your Audio

Find the p-pop
Find where the p-pop happens in your recording by listening in headphones
Highlight JUST the “p” Sound in Your Editing Software
Zoom in and highlight ONLY the “p” (or other plosive sound like “b,” etc.). Be careful not to select any of the vowel sound that comes after the “p” sound.
Apply EQ Effect
Apply an equalizer effect (EQ) to the “p.” Reduce the low frequencies in a slope going down and to the left, starting with about 200 Hz.

How to Fix SSS-Sibilance in Your Audio With Sound Editing Software

April 1, 2017 by Ken Leave a Comment

Why sound editing software can be your friend. One common problem with recording the human voice is sssssomething called ssssssibilance. If you didn’t already know what “sibilance” meant, my odd spelling above may have clued you in. It’s a sharp, biting hissing sound that happens whenever the recorded voice utters the “S” sound. You’ll be listening to the recording, and everything will sound great, until the speaker/singer utters the phrase “she’s a sensation,” and pierces your eardrums.
The good news is that you can use free sound editing software to fix this!
There are lots of reasons why this might happen, over-compression (see more info on compression here:Improve Or Ruin Your Audio With an Effect Called Compression and Vocal Compression Using Reaper’s ReaComp Effect Plugin), wrong kind of mic for that voice, too much reverb effect, etc. Just know that if you do any recording or audio editing of human voices, you will periodically be faced with sibilance that cannot make it onto the final version of the audio file. So what do you do?
You’ve may have heard of something called a “de-esser,” yeah? de-essers are effects that are designed to filter and tame sibilance, while leaving the non-sibilant part of the audio alone. If you are familiar with the range of human hearing and the use of EQ (equalization) tools in audio (see my article about EQ here: What is Equalization, Usually Called EQ?), you’ll know that people can only hear sounds that exist between the frequencies of 20 hertz (HZ) and 20,000 Hz.
In practical terms, most adults are going to have trouble hearing anything over about 13,000 Hz. What’s most interesting about this fact is that certain familiar sounds “live” at predictable frequencies. No it IS interesting! Don’t argue with me;).
If we know, for example, that the “bass-y, boom- y parts of a bass guitar will most often be found around 80-100 Hz. So we can then we use an EQ to turn down (or up….but usually down….never mind) the bass by ONLY turning the volume down around 80-100 Hz. Likewise, high sounds like the sizzle of a high-hat, can be found hanging out around 6,000 Hz (or 6KHz for short). So if you knew that vocal sibilance mostly hung out between 4 KHz and 10 KHz, you would know where to start looking for your particular brand of hissiness so you could fix it.
A de-esser is simply a tool – found in most sound editing software programs – that zeros in on a certain group of frequencies (like 4-10KHz or 5-8KHz, etc.) and will turn the volume down in that region, but ONLY when it gets TOO loud. Smart tool huh?
As long as the “s” sounds are normal for human speech, they are left untouched. But the instant they get unnaturally hissy, they’ll get turned down just enough to make them sound normal. It takes some playing with the settings to get this just right. Overdo, though, it and your singer/speaker will develop a lovely lisp.
If you don’t have a de-esser, a compressor, or an EQ (de-essing is really just a combination of compression and EQ), there is one sure-fire way to fix sibilance which is my first choice, especially if the audio is short, like in a podcast intro or a short song. Instead of treating the entire file as you would do with a de-esser, just LOOK at the audio in an editor.
It’s so cool that we can use our eyes to edit audio now. Isn’t it? Sigh, OK I’m a geek. Anyway, you can usually see sibilance on a computer screen pretty easily, using any sound editing software available. The squiggly blobs get all bunched up and dark for a bit. In the picture, you can see the word “serendipity’ recorded. The blue blob at the beginning.
Just follow the cursor and when you hear the sibilance, you’ll likely see it as well. Now zoom into JUST the sibilant sound and highlight it. Use the editor’s volume control to turn down ONLY the “s.” Listen to the result and if that didn’t fix it all the way, or you gave the speaker a lisp, just “undo” and try again until you get it just right. Rinse and repeat for each offending sibilant sound, and voila! Your hissing snake problem is fixed!

I recommend the latter method of fixing sibilance in your audio if the file is only a minute or two or less. For longer files (audio books, etc.) you’re probably better off using a de-esser.

Voice Over Recording Tips: Editing Conversations In Reaper

March 26, 2017 by Ken 4 Comments

If you have ever been asked to record and edit a conversation between two people, say, for a voice over job, then you are probably aware of the logistical problems this can cause. The client usually has visions of just getting the two people together around a microphone and simply reading their parts at the appropriate time. Sure, that would be OK if you always had both people available at the same time, along with two great microphones, a large enough space for both people to occupy at the same time, etc. But these conditions are not always available to us.

Boy-Girl-Boy-Girl

So for the sake of the example, let’s say you only have one microphone and you have to present the client with a conversation between a man and a woman. This is a situation I had monthly a while back and it seemed to take forever to get it right. Also, the boy (me) recorded all his lines in one long take, creating one long audio item in a track, and likewise for the girl. One segment of the job required that the bog-girl voices alternate with exactly 3 seconds between them. That made the job even longer, especially since I was doing it manually, clipping and trimming each bit of dialogue, and then using the grid (set to seconds and minutes) to drag each clip into place and ensure a 3-second space between each. Yikes!

Time Saving Tips

By the way, we’ll be using the excellent audio recording software called Reaper for this example, but similar tools can be found in other multi-track recording programs.
The first lesson I learned was to color-code. I used blue for boys and pink for girls. Yeah, yeah, it seems sexist but it works! Besides, my wife (the “girl voice”) likes pink. Anyway, in Reaper you simply right click on the audio item which opens a pop-up menu, go to Item Takes and Colors/Set Items to Custom Color. If you end up putting both voices on one track (which is easier when putting a 3-second gap between each), this becomes very helpful.

Slice and Dice Automagically

The next bit of time-saving automation was the Auto Trim/Split function. What this does is allow you to slice one continuous audio file into several separate audio items in a track based on when there is silence and when there is speaking going on. This was huge! I had been slicing (using the “S” keyboard shortcut) just before and just after each phrase, and then dragging the edges of the resulting clipped audio item in to get rid of the silence. That was 4 different operations (2 slices and 2 drags) for every phrase! Multiply that by dozens of phrases for each voice and you have a LOT of work. But with Auto Trim/Split, you select the entire long audio item in the track and hit one keyboard shortcut (you can set your own – mine is “ctrl+~”) and boom! Every phrase becomes its own item, perfectly trimmed on either side. See the picture at the top of the article where this has been done to each voice). That one discovery saved me about 20 minutes per voice!
Below is a video that shows you step-by-step how to use the Auto Trim/Split tool in Reaper to save you huge amounts of time.

The other thing that was taking a long time was spacing each voice, alternating boy-girl-boy-girl, with exactly 3 seconds between each phrase. As I mentioned earlier I was doing this manually until I discovered the Reposition Items tool in Reaper. [Update: Reposition Selected Items (as it is now called) is not part of the native Reaper set of tools. You need the free extension set – SWS extensions – by just going here: http://sws.mj-s.com/ and downloading the SWS extensions file and installing it by executing it. Then it will be added to the Actions list in Reaper]. You select all the phrases in a track, open Reposition Items, and simply tell it how much space should be between the items. This is very like the “distribute” function in many graphics programs. To put 3 seconds between the boy and girl voices, though, requires both blue and pink to be on the same track. But that was pretty easy. Just space them out and slide them until they are well and truly between the blue phrases in the adjacent track, select all the pink phrases, and simply drag them up onto the track with the boy/blue phrases. Now that they are all on the same track, select them all (you can lasso them all by holding down the right mouse button and dragging over them), open Reposition Items, and put 3 seconds into the Time Interval window.
With those tools I was able to cut my processing time for this job by about 50%. Even if you don’t have to space them out evenly or put them on one track, I’m sure you’ll find a combination of these tools to be very helpful if you have to produce a voice over job with more than one voice.
Cheers!
Ken

The Difference Between Sound Editing and Sound Mixing

February 26, 2017 by Ken 3 Comments

There are two academy awards for audio recording and producing, which are Sounds Editing and Sound Mixing. The 2017 awards were awarded as follows:
Sound Mixing – Andy Wright, Peter Grace, Kevin O’Connell, Robert Mackenzie for Hacksaw Ridge.
Sound Editing – Sylvain Bellemare for Arrival.
Now you may be asking what the difference is between these two audio categories. Don’t worry, you’re not alone. There is even some question, at times, about whether the academy members themselves understand the difference. It turns out they often do;). But the difference really isn’t as hard as it is sometimes made to seem.
The sound editors are in charge of creating the sounds for the film, including the sound effects and sound design elements.
Once all the audio has been recorded – including the sound effects, sound design, dialogue and music – the sound mixers combine them all and blend them into the film, making all the sound work and play well together.
It’s been described – if this helps – as the difference between a film’s director (the sound editor) and the cinematographer (sound mixer).
So now you can explain it everyone at work if they happen to ask. Think how smart they’ll think you are;).
Cheers!

How To Use An Audio Editor To Remove Saliva Noises From Voice Recordings

July 17, 2016 by Ken 22 Comments

Using an audio editor, you can REALLY improve your voice over recordings. This article and video shows you how to get rid of saliva noises when recording voice overs. Of course it works for any kind for any kind of vocal recording where your mouth is close to the microphone.
These saliva “clicks” – along with “p-pops,” (for how to remove those, see our article How to Fix a “P-Pop” in Your Audio With Sound Editing Software) are probably the two most common problems we experience when recording vocals.
Just this past week, I was helping a voice-over actor to improve the quality of her recordings. She had just been turned down for a job because, according to the client, there were too many saliva noises in her audio. When I listened to one of her recordings, I knew exactly what the client was hearing. I struggle with this on my own recordings, so I have experience doing everything I can to prevent that spit noise. But usually I cannot prevent it all, so some saliva noises get recorded.

So If You Can’t Prevent The Noises?

Once the noises are already in the recording, the only choice (other than trying to record again…and again) is to use audio editing tools to remove the offending saliva noises. My editing tool of choice for this is equalization (or “EQ” for short). To brush up on what EQ is, see our article What is Equalization, Usually Called EQ?
It is almost always best to prevent a problem rather than have to fix it later. So here are some things you can do to keep those spit sounds out of your recordings in the first place:

Eat tart apple slices – This helps my wife and me quite a lot. Try different kinds of apples (or any type of food, for that matter), but we like Pink Lady apples for this.
Drink water – This is probably the most commonly offered advice for keeping that saliva from sticking under and around your tongue. But again, try different things. I’ve heard of people using unsweetened tea and even beer for this:). That could be a fun voice-over session:).
Mouthwash – Ironically, I find that the times when my mouth feels dry is when the saliva noises are the worst. You might try one of the moisturizing mouth rinses like Biotene to help with this. Biotene also makes a convenient moisturizing spray.

Fixing The Saliva Noises After The Fact

Sometimes no matter what you do, your saliva finds its way into your recording. When that happens, here is what you do (which is shown step-by-step in the video below):

Open your audio in an audio editor

Though it is possible to do this kind of editing in digital audio workstation (DAW) software like Reaper (usually more geared toward the recording and mixing of audio), I prefer to do it in a program more focused on editing. Examples in include Adobe Audition, Sound Forge, and even the free Audacity. There are many others of course. I used Audacity in the example below, since the video is an excerpt from our course, The Newbies Guide To Audio Recording Awesomeness 1: The Free Recording Studio.
Find the saliva noises in the recording

Listen for where the saliva spit noises are located in the audio file and make note of where they are. Then highlight/select the first bit of audio containing the offending sound. We’re going to use EQ on as small an area as possible so we can be surgical about this. It we apply EQ to large areas of the recording that do NOT contain saliva clicks, the resulting voice could sound a bit muffled. The more we can surgically remove these noises without affecting the audio around it, the better.
Hit it with EQ

When we used EQ to fix p-pops, we reduced frequencies around 250 Hz and below. Those are low, bass-sounding frequencies. But for the saliva clicks, we need to focus in the higher frequencies from about 6,000 Hz (6 KHz) and above. See figure 1. You’ll see in the video how to do this using a graphic EQ setting in Audacity’s equalization tool.

As promised, here is a video showing you how to do all of this:
http://homebrewaudio.wistia.com/medias/wk6zbs5ku0?embedType=async&videoFoam=true&videoWidth=700
There you have it! Another way to clean up your audio quickly and easily, as long as you have a good idea what to do, which is what Home Brew Audio is here to do for you:).
Now go forth and produce better audio!