Finding an acoustic environment (Voiceover)

by Tom Johnson on Mar 4, 2010
categories: screencasting

At the upcoming STC Summit, I'm presenting a session called "Developing a Personal Voice in Audio." In this presentation, I'll explain how to "deliver video tutorials with a friendly, personable voice by implementing several audio techniques common to professional voice talents and sound engineers.

One way I prepare for presentations is by writing a series of blog posts about the topic. So over the next two weeks, I'm going to write 10 posts about developing a personal voice in audio.

I admit that I feel like a novice with this topic. I'm not a voiceover professional, sound engineer, or e-learning guru. I do podcasting and screencasting. But voice is a topic I've been enthusiastic about for a long time.

Finding an Acoustic Environment

For several months I've been looking for a quiet room to record screencasts at my work. Our building has four floors for more than 600 IT professionals. I investigated more than 20 conference rooms, poked my head in empty offices, walked around unfamiliar floors, inquired here and there.

When people see me looking, they don't understand what I mean by a "quiet" room. What does quiet mean? Stop and listen to the sounds around you. The fan, a ticking clock, a rumbling from a dishwasher or dryer, the hum of the lights, the sound of non-descript white noise, voices from a neighboring office, or cars passing by outside. The sounds are subtle, but when you start recording, these noises amplify onto your audio track.

That's why you need a quiet room. If you have your own private office, great. If you have to schedule time in a conference room, that can also work. You usually have to work with what you've been given.

But let's say you want something more -- your own private recording room, where you can set up your equipment, lock the door, record is perfect silence, and come and go whenever you please, without worrying about someone playing with your expensive microphone.

After weeks of searching, I finally found that room. On the ground floor of our building, I located an unused observation room that's part of a usability lab which, sadly, no one uses. The walls are lined with cloth panels. There is no fan. The room is isolated from other rooms. There's a wired connection for internet, and at my request, a locksmith added a lock on the door and gave me the key.

I set up two monitors (hauling them down from my regular cube), a docking station, mixing board, my microphone and other equipment. It's as close to recording in a studio as I will ever get. I've actually been holed up in that room ever since I found it. The solitude is both rejuvenating and helps me be productive. Most importantly, I can record without any ambient noise.

Characteristics of an Acoustic Room

When you're looking for an acoustic environment at your work, look for a room that has these qualities:

1. Cloth paneling on walls. If the walls don't have any kind of cloth or soft surface, the sounds will bounce and create echoes and boxy effects. As a test, clap your hands once and listen to the sound. Does it immediately die, or does the clap echo around in the room? You can bring in blankets and drape them around the walls to dampen the echo, but usually you can't do this in a company conference room. You could also invest in some portable acoustic foam or a reflexion filter, like this one.
2. Fan-free. Usually conference rooms have fans (as part of a ventilation system), but the smaller rooms often don't, or the fans are less noisy. If you can actually turn the fan off, even better. Although you can apply post-processing to edit out fan noise (using software like SoundSoap), and you can use a microphone that won't capture many of the sounds from a fan (i.e., a dynamic cardiod mic), the hum of a fan will generally add a static background noise to your recording, which becomes problematic later on when you try to silence the gaps (to silence your breathing noises, for example). At the very least, if all the rooms have fans, pick the room with the least noisy fan.
3. Unschedulability. If you can find a room that can't be scheduled by other people, or if it's a room that you can schedule for weeks at a time without interruption, that's best. Because otherwise you may have to drag your equipment in and out of the room each time you want to use it. In a later post, I'll explain why dual monitors makes life easy. Do you really want to drag in two monitors and all your other recording equipment in an out of a conference room multiple times a day?
4. Isolation from other people. Conference rooms and offices in workplaces are usually located next to other rooms and offices because proximity to your colleagues enables collaboration and exchange. But if the walls are thin, those voices carry over to your room at the worst times (right in the middle of a perfect recording). You need to find a room that is isolated from other rooms as much as possible.
5. Lockable. Once you set up your fancy recording equipment, it's nice to be able to leave everything as is and walk away, locking the door behind you. If you can add a lock on the door, you can secure your equipment in a convenient way.
6. Windowless. Look for a room with either no windows or low visibility. At my work, we have convenient team rooms right next to every row of cubes. But the team rooms have large windows on both sides. One time (the only time), I recorded some tutorials in one of these team rooms, and within 10 minutes, my colleagues were peering in the windows to see what I was doing. One colleague saw the microphone and immediately entered, saying "Hey Tom, what's up?" with a big smile. After I finished and went to a meeting, another colleague put a post-it note on my microphone that said "Karoake anyone?" The less other people see you, the better.

Why is acoustics important?

One of the key advantages in finding (or creating) a good acoustic environment is being able to reproduce the exact same sound when you're editing your recordings. If you have to constantly change rooms with different acoustic environments, you can't easily splice in patches or fixes to your recordings. By maintaining the same environment and setup, you can fix little bits here and there if you make mistakes. As you're editing the audio, you can decide to re-record a sentence here and there, and it will sound seamless because you're in the same acoustic environment.

If you can't find the right acoustic environment, that's all right. Make do with what you have. In a later post, I'll talk about using a dynamic cardiod micrphone, which does a good job at capturing the immediate sound in front of it and blocking out peripheral sounds.

Next: 1.4 Sounding natural (Voiceover)