How To Teach Online: Recording Quality Audio

Hello!  I’m Mattias Andersson.  I'm an instructor at A Cloud Guru and I'm going to teach you how to capture high-quality sound for your online teaching lessons. This is the third lesson in a multi-part series, so feel free to revisit lesson 1 or lesson 2 for broader context and even more useful tips.

Now, I want to lead with the most important feature, which is audio. Without any sound, videos become confusing, but without video, audio can still function to tell a story. This applies to your online teaching because it emphasizes that the sound you capture is more important than your video.

That said, please don’t come away from this thinking that your video is unimportant. Because video is also very important—just not quite as important as your sound.  And you’d be silly not to pay attention to both, right? The guideline you should remember is that clear audio is more important than good video, so it’s generally better to invest in improving your sound capture than making things look perfect.

So, let’s start to tackle that audio side. When I create online videos for ACG learners, you'll often see me with a special microphone on my person, as opposed to relying on the audio built into my camera. Why is this? Well, because I want to prioritize audio, and the microphone on my camera can only do so much. To create clear, high-quality audio I opt for a lavalier, or lapel microphone. It helps create a broadcast-quality sound as it's much closer to my mouth than my camera's microphone is. 

This doesn't mean you need to buy a mic like mine, because your situation may be different, but the distance between the speaker and the audio equipment is an important thing to consider throughout your recordings. Even on everyday conference calls, it's important to understand the limitations of your computer's built-in microphone and how far it is from your voice.

When the mic is close to my mouth, the sound it captures is much clearer than when it is far away. But being too close can also be bad, though, and can capture some sounds like lip-smacking and emphasizes plosives like the P in Peter Piper picked a peck of pickled peppers.

Capturing sound is all about the ratios. Actually, it’s mainly one particular ratio: the Signal-to-Noise ratio, or SNR. In the SNR, the signal is the sound you want to capture—like your voice. The noise is all the other sound—the stuff you don’t want to capture. This could be the cars on the road outside, or a device humming, or someone else talking around you.

Now, imagine a situation with other people talking—I’m sure you’ve experienced that before, right? What do you do if you’re having a conversation in a busy room and someone is having a hard time hearing you? One option is to yell. If you get louder than all the other noise, then your audience can hear your voice. And this is something you can apply to your own online teaching.

I don’t mean that you should actually YELL YOUR LESSONS, but speaking too quietly will make it much harder for the microphone to pick up your voice. And speaking with a full voice ties into other things we’ve discussed in other episodes, of needing to make sure that you speak with enough energy to engage your students with what you’re teaching.

But there’s another thing you instinctively do to be heard, too: you stand closer together.  Even if you yell as loudly as you can, your audience will never hear you from the other side of town, right? That’s clearly too far. And even being on the other side of a busy room will make you impossible to hear. You need to get right up close to the listener. In fact, you might sometimes even put your mouth right up to their ear and cup your hand—then even your whispers could be heard above the noise.

This is the exact same concept for microphones, of course. That’s why I put my mic close to my mouth, but not physically touching it. And you can do the same. The microphone doesn’t need to be expensive or fancy. It mostly just needs to be close to your mouth. One of the best ways to do that is to buy an inexpensive wired microphone that you can clip onto your shirt, near your collar. Some lapel microphones even plug directly into your camera, and some can record the audio on your smartphone.

That's assuming you’re shooting a video and the student will see your face, I mean. If you’re only recording audio—over slides, or something—then there's no need to bother with a clip-on mic. Several of us at A Cloud Guru recorded our first courses on microphones that cost us less than fifty dollars. I still have mine today. Just make sure you put your face up close to whatever you’re using. But not too close, remember. And you can figure out what's too close by recording yourself and listening. Start by saying "Peter Piper picked a peck of pickled peppers."

And while you’re listening, you should also make sure that you’re not getting a bad echo.  If you’ve got your mouth close enough to the microphone and aren’t right by a wall, then this may not be a problem for you, at all—because the echo noise is many times farther away from the mic than your voice signal. But if you do hear an echo, you can try putting up soft things—like hanging blankets or sweaters on your walls.

Another suggestion I give new online instructors is to plug your mic directly into the computer or camera recording the display component of your lesson when possible. The advantage of this is that recording the audio and video together makes things easier to edit because they’re synchronized.

Have you seen any behind-the-scenes stuff about making movies? Often you’ll see the clapperboards they use to mark the beginning of each take.  But they don’t just film the clapperboard—they also speak the information from it and CLAP it together. That CLAP is what lets editors sync up the audio track with the video. Because if they aren’t synchronized, then it feels really wrong.

So, if you are recording your audio and video separately, always start both of them recording and then CLAP your hands together. Remember to make sure you’re in the frame of the camera though, or it won’t help. Then, when you’re editing, match up the video frame where your hands meet with the bump in the audio waveform for the clap. And don’t worry if you’re not totally sure what I mean just yet; it’ll make more sense when you try it out for the first time.

Another important feature I want to mention about microphones is the gain. Gain is the sensitivity of the microphone—kind of like the volume, but for the recording side.

If the mic gain is set too low, then it won’t hear anything. It's like a hearing aid that’s run out of batteries or been turned off. And if you try to amplify a very low gain signal, it’s like trying to zoom in and count the hairs on someone’s head in a picture taken with your phone, from outer space. OK, so that example may not be something that you or I have ever experienced, personally, but hopefully you can imagine it and remember that this just won’t work. If you try to do this with your sound, it will be distorted and possibly very noisy, too.

But the opposite end of the spectrum is just as bad: when the gain is set too high, the sound waves get “clipped” and what you record sounds terrible. It might be possible to make out what you’ve said, but it will still really strain your students’ ears, at best. At worst, it’ll be completely unusable audio.

You need to set your gain "just right". Imagine Goldilocks coming over to your place and setting up your microphone for you. And I know what she would do. She would go into your microphone’s test mode to see where the sound level is registering, have you talk as loudly as you should when you’re recording, and then make sure that the mic’s signal bounces up high but never goes red or hits the very maximum possible. That’s it! And actually, you don’t even need Goldilocks’s help; I’m sure you could do this yourself.

Finally, I want to touch briefly on noise reduction. In software I mean. Here’s the thing. It definitely is possible to apply some noise reduction to your audio signal, during your editing stage. And it can sometimes help. But there’s no question that it will not sound nearly as good as if you would have eliminated the noise at the recording stage, instead.

It’s kind of like dropping a piece of bread in the mud—sure, you could try to clean it off and get most of the dirt out, or wash it with water and deal with it being a bit soggy. But wouldn’t you just rather have kept the thing clean, instead? Benjamin Franklin may not have been talking about recording videos for the Internet when he said, “An ounce of prevention is worth a pound of cure”, but it definitely applies, here.

Now that you're an audio guru  we can look at video next. Get it? Look at video? Ahaha? 

OK… I’m sorry.

But this lesson has already covered enough good stuff, so it’s a good place to break off and let you digest it. Sound good? Think about your own situation: What microphone options do you have available to you? Which one would be the least hassle for you to use? And which one can get closest to your mouth when you’re recording? And if you’ve tried them out, which one sounds best to your ear? Especially when you adjust both the gain and where your mouth is.

I hope this helps you record better audio for your online teaching.  And if you have any more tips you'd like to share, please leave a comment on the YouTube video to help others. Stay safe, and keep being awesome!

ACG instructors craft each course to keep you engaged and motivated on your learning journey. Explore our course library.