Tips For Room Echo Reduction


Sound is a mechanical waveform, which is a fancy way of saying that it travels through space and interacts with particles along the way. Depending on the space, you may hear a lot of reverberation from the sound waves reflecting off surfaces, which can be disruptive in a conference room setting. Below, we’ve outlined the basics of room echo reduction, including the difference between echo and reverb, the steps you can take to reduce reverberation, and more.

Echo vs Reverb

Let’s say you’re in a canyon and shout at the top of your lungs. Shortly after shouting, you should hear an echo of the original sound, which bounced off the canyon and came back to your ears. There’s a perceptible delay between the original sound and the echo, which takes at least 0.1 seconds to return to its origin.
Meanwhile, reverberation (or “reverb”) takes less than 0.1 seconds to reflect off nearby surfaces and return to your ears. There should be no perceptible delay between the original sound and its reflections. They should blend together into one “wet” sound that lasts a little longer than the original source. When hosting a conference, you’ll have to consider both the room reverberation and the conference system creating unwanted echoes.

Acoustic Echo Cancellation

Many of today’s conferencing solutions including digital signal processing (DSP) features that optimize the audio signal for clarity. One of the most important DSP features for conferences is acoustic echo cancellation (AEC). This feature prevents your microphone from picking up the other party’s audio from the loudspeakers and sending it back to their conferencing system as a pesky echo. To avoid this, AEC analyzes your audio going into the microphone and the far-end audio delivered through your speakers. Then, it cancels out any far-end audio that was captured on your microphone. It’s a must-have DSP feature for any audio or video conference.
To work properly, every microphone needs its own dedicated AEC, because the mics are in different positions that capture unique echoes. For individual use, you can also mitigate the issue by wearing a headset or earpiece so that no far-end audio is picked up by the mic.

How to Reduce Reverberation in a Room

There are a few practical solutions for room reverb reduction that don’t require costly investments in cutting-edge technology. Here’s what we suggest:
Hang Soft Materials on Parallel Walls
You can decorate your conference room and reduce reverb in one fell swoop. Hanging soft canvas or cloth artwork (such as textiles) can minimize wall reflections, especially when the art pieces are placed on opposite walls. However, you should avoid oil paintings if possible, because the dry oil is hard enough to reflect sound.   
Add a Rug to a Hard Floor
Some conferencing spaces are designed with a cool minimal aesthetic, but a concrete or hardwood floor can add unwanted reflections to the room. Adding a large rug around the conferencing area will dampen the unwanted reverb, while also making the room more inviting.
Hang Echo Reduction Panels
There is a wide variety of acoustic panels for sale online. These panels can dampen wall reflections and reduce sound leakage into adjacent rooms. You can also assemble your own panels with a package of acoustic insulation and some thick fabric. There are a ton of free DIY tutorials on YouTube that will teach you how to create your own panels and save money. 
Place a Bookcase and Dense Objects in the Room
When moving into a new home, you probably notice how boomy it sounds in the empty space before bringing in the furniture and boxes. That’s because objects dampen and diffuse sound in a room. When you talk in an empty space, your voice bounces off the walls with almost no interference, so the reverb is noticeably louder. By adding a bookcase, more furniture, and a few decorative objects to your conference space, you’ll soften the reverb to a pleasant level.

If you found this article useful, you might also enjoy our list of 7 common things you might find on a modern conference room table.

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