Doctor, We Need an X-Ray! STAT!
"This man's...voiceover is suffering from acute clickitis. There are mandibular clicks, lingual clicks, and...and what's this? This man is breathing too hard in all the wrong spots. What do we do? WE NEED AN X-RAY!"
Ok, maybe that would be best left in a medical drama. But the problem is real! What happens when you have that dreaded problem of (cue the dramatic incidental music) Clickitis. You know, when your tongue or your mouth makes some odd clicking noise when you speak. Normally you don't notice it, but as a voice talent, its annoying.
Finding the click is about as easy as finding a ghost in the dark. I mean, its dark, they're ghosts, and... Nevermind. You get the point here. Its hard, lets just put it that way.
Recently I was doing some editing for a local voice talent here. The project: An Audiobook. Hard enough eh? Tell me about it (no don't). I was tasked with getting rid of the occasional mouth click - which in his case were not common, but when they happened, oh boy.
So I got online and researched some of the best ways to remove mouth clicks. I already knew about iZotope RX series plugins for DAWs (Digital Audio Workstations). I wrote a blog about this. Check it out here. It goes into the plugin I use and the technique, so I won't reiterate that now.
Instead, I want to delve in deeper into how to read a Spectrogram.
What is a Spectrogram Anyhow?
I'm glad you asked. A Spectrogram is "A spectrogram is a visual representation of the spectrum of frequencies of a signal as it varies with time. When applied to an audio signal, spectrograms are sometimes called sonographs, voiceprints, or voicegrams." according to Wikipedia. It's an incredibly useful tool in finding all sorts of issues involving clicks and other anomalies.
As mentioned, I was tasked with listening for and removing known clicks in an audio track. Now, depending on what you're recording, clicks might not be an issue. Say you're recording vocals for a song. I don't care how hard you try, unless your voice is soloed and the mic is right up on you, you're not ever going to hear clicks. However, when you're intently listening to "The Life of Delia: A Midwest Love Story" while you're driving, you might be distracted with too many clicks or pops or any other problems, all the while trying to pay attention to Delia being swept into Chad's arms, her heart rush[click]es in intensity as he brushes her ruby hair out[click] of her soft, gr[click]een eyes and gently whispers.... Ok. Enough of that. You get the idea. Chad Good. Clicks bad.
But, How Do You Use Spectrograms To Find Clicks?
See, you're all full of great questions. When I was working with RX 8 (in my case), I knew it had a De-click setting and you could automate this process. Great right? No. I quickly found that running the De-click on the whole file might produce some unwanted side effects. Kinda like my meds. I wake up in the morning and find out that my eyes are now yellow and my face has broken out.
Anyhow, side effects. Right. So some spots seem to be dropping out or sounding crackled. Wait, I'm introducing anomalies! Whisky Tango Foxtrot! I need to go into surgery mode with this and bring up the o'l X-Ray...er, spectrogram. Hang on folks, we're about to become surgeons.
Get Your Scalpel Ready!
Below is a segment of a recording I did. Note on the top are little red dots. In my DAW, Reaper, I can mark off where in the recording I have clicks. Most DAWs can do that too -- even Audacity!
And below is a segment of that recording where you'll see the wave form up close. Notice where the click is?
Of course not. You can't. You're looking at the patient in the O.R. Now, lets look at the X-Ray!
Can you see it now? Well, in this one, its a bit elusive. Admittedly, the click wasn't very pronounced. Let me get a CT Scan...
Ahhhh. See it now? That blob towards the top of the circled area. I did the whole area to show that there is also some right below it. Harder to see, but its there. Now, if you go back to my blog where I talk about iZotope, you'll find out what tools I use to remove the click.
One thing to note, This anomaly happens about the 6KHz range. Most clicks like that will happen there, so that is a great place to look!
As I did in the iZotope blog, I am going to use the Time-Frequency selection tool to do some surgery. Best thing about using this type technique is that you can not only remove an area, but you can focus on the specific frequency where it occurs without disturbing the rest of the recording in that spot.
See, the blob is gone. When I listen to the recording, no click! Take a listen here.
Doctor, I Think He'll Make It.
Sure we've made it. We've made it better and you can too by utilizing the spectrogram to find spots in your recordings that drive you insane (and for me, that's a short trip). Use the spectrogram in your DAW, in an editor such as iZotope or Audacity and make your voice overs fantastic!
Cheers and until next time, go record something.