VO Studio Acoustics: Reflecting on Reflections in our Recordings

How do we learn to recognize good sound?

We’re surprisingly immune to noticing imperfections in our VO recordings – especially reflections or echoes. It is likely related to our developed social orientation, and the magic of learned language. In short, when people talk, we listen. We focus upon what is being said, and our brains do a wonderful job actively filtering out any distracting sounds not coming out of the speaker’s mouth.

Why we don’t hear stuff

The more urgent and immediate a message, the less likely we are to notice those “other” things like echoes or background sounds.

This physiological evolution works really well for communicating ideas. Even though humans are basically a soft, fairly defenseless, somewhat tasty snack compared to most animals, we’ve done reasonably well as a species. Adaptation of verbal communication into language allowed the sharing of generational wisdom. That’s pretty much what allowed us to flourish over time.

Our ability to selectively focus upon specific verbal information increased as well, allowing us to filter out the extra noises and distractions with our brain.

Microphones hear EVERYTHING!

However, a microphone does not have a brain attached (well – so far…). When we place that simple transducer in a space, it records everything. People complain about microphones being “sensitive…” But being sensitive to subtle changes in air pressure is their job. That is what they are supposed to do for us. We just get surprised by all that other stuff the microphone captures.

The biggest distraction in recordings is generally reflection. Sound is simply a change in air pressure – a vibration of atmosphere surrounding us. When speaking out loud, we create a specific pressure change by pushing air through our vocal folds. That pressure change rushes out like a wave. When that wave hits something hard, the energy is bounced back – just like waves in a pool or bathtub. The waves may come right back at us, or they may skip away like a rock on the surface of lake – heading into a direction we didn’t quite expect but continuing to carry the energy.

The content – our words – are the “direct” signal, straight from our mouth to the sensitive ear of the microphone. Any indirect waves – those splashes bouncing around the pool – come back to our microphone at different times – slightly after the words we spoke.

If it takes a long time for the indirect wave to return, we call it an echo – a distinct repeat of the sound after a period of time. That requires a larger space in order to make that occur. If you are getting that kind of an echo, that’s a different issue.

Since we tend to do our recording in smaller spaces, the indirect sound does not take too long getting back to us. These “short echoes” layer in with our direct sound. These are the “primary reflections” that bounce immediately back into our microphone, but aren’t arriving at the same time as the direct signal. That impacts the clarity of our recording. We may say it sounds “echoey,” but it’s all tangled up with the direct signal. Untangling that is pretty complex.

Acoustic reflections cause problems

Those primary reflections of our voice significantly change how we sound. When you combine a bunch of waves, the “phase” of those waves interact in specific ways. The out of phase waves start to cancel each other out, meaning certain frequencies are reduced or eliminated. That’s why you can sound weirdly muffled or “thin” in a recording (assuming you are talking into the correct side of the microphone from an appropriate distance).

Fixing those reflections

How do we stop those reflections? Achieving that requires soft, appropriately dense, absorptive material that makes the sound waves lose energy – just like the breakwater around a small boat harbor.

The first thing I locate in a recording space are all the hard surfaces. In most cases, you’ll have bare undersides of shelving, copy stands, hardwood floors, or other areas which negatively impact your sound. When doing this, most newer voice actors notice all sorts of hard surfaces when looking at the microphone.

But there’s somethat that is easy to overlook… (cue creepy horror movie voice) “there’s something behiiiiiiind you!”

Final room check: Turn around! 

Yep. What do things look like back there? An untreated door, wall, or wide open space matters. A lot. Whether it’s the unpadded door to your closet, or the big open room behind you, the large area in back of you, all of those situations will strongly impact the quality your recorded sound. It’s easy to get focused on surfaces in front of you when you face the mic, but it’s important to take into account what is happening in the rest of your space. 

Since most VO mics have a cardioid pickup pattern, it mostly wants to “hear” the sound from behind you. When you turn around, you are looking at the reflection sources that the microphone is most likely to capture. Cover that stuff or add a PVC framed soft back wall. That’s much more important than even the ceiling in most recording spaces. 

Want a quick way to test? Clap your hands sharply. If you hear any kind of echo or “extra” sound, it is probably a good idea to add more absorption.

Can you have too much treatment?

Honestly? No. Not for voiceover work or audiobook narration.

We want to capture your voice without the extra sounds bouncing around the space. If a commercial producer needs it to sound echoey, or an ADR projects needs a certain type of acoustic response, that will all get added in post-production. We are always better off with less reflection.

Additional studio setup resources on this site –

Setting up a home studio: Thwack That Echo!
Setting up a home studio: Acoustic Panel Possibilities
Setting up a home studio: Three Steps – “E – R – P”
Reverb is not “Noise”
Problem Solving in the studio: When it sounds “Different”
Rumble in the Home Studio
Studio Upgrade Series – Refitting a Vocalbooth with ATS Panels

How does your space sound?

If you would like a no charge review of your audio quality, you can upload your audio sample through this page.

This information recently went out to my email community. If you would like to join in, please take a moment to share your contact information through this sign up form. Thank you.