To eliminate echo or reverb in your home or a commercial space, it’s helpful to understand the differences. The solutions can be similar, so some of you may be thinking “I don’t care! Just fix my space already!” If that’s you, we hear you. Get out your phone and call our main number or scroll right past all this and submit your room information to us. We’ll get you on the fast track.

ECHO

An echo is the distinct repetition of the original sound. It must be loud enough to be clearly heard above the general background noise in a space. You’ll hear them in large rooms like gymnasiums, cafeterias, and high-ceiling conference rooms. Echoes mostly exist in large spaces because it takes time for the sound waves to reflect off a hard surface and travel back to the listener, but it’s possible for to hear echoes (like a “flutter echo”) in small spaces with parallel walls.

Reverb

Reverberations mostly occur in small spaces when the original sound is quickly reflected by multiple surfaces. You hear the reflected sounds so quickly that they pile on top of each other, resulting in garbled noise. Have you ever sung in the shower? You likely heard a weird, off-key version of your own voice thanks to reverberation. Reverb can be present in larger spaces, like an open office or in restaurant noise and gym noise. Without proper acoustical treatments, the large number of people talking results in substantial noise buildup.

Difference betweem Echo and Reverb

The echo vs reverb debate can be very confusing becuase the two are very similar concepts, the difference only in reflection time, where reverb has very short reflection time while echoes are much longer. Hence, why you hear reverb in a smaller space like a shower versus much larger spaces needed for echoes. Check out this guitarist giving a great example of the different between the two sounds!

The first step in deciding how to reduce echo in a room is whether or not people are annoyed. What makes them the most annoying? The good news is studies have been done, so we have some data to go off of. Based on the sound level of the echo above or below the direct sound level (in dB) and the time delay, we know whether greater than 50% of listeners will be annoyed. The chart looks like this:

When a sound is reflected nearly as loud as it originated, as clearly as it began, it’s hard to hear anything else. The time delay is the real kicker though. The longer it takes for the echo to be reflected (length of time is relative to distance from reflective surface), the more irritating it is. Think about it: how annoying is it when you’re on a Zoom call and you keep accidentally talking over another person because of the time delay? The principle is the same here.

Reducing echoes in a space is often complicated and requires specialized expertise. For learning’s sake, we’ve included a couple of common solutions, but you’ll need to talk to an acoustics expert (Yoohoo! We’re here!) for customized advice.

1. Install sound-absorbing wall treatments

Use Acoustic Pro fabric wrapped panels to soften hard surfaces and absorb sound. For a smaller room, use the 40% Rule to figure out how many panels you’ll need (length of room x width of room x 40% = square footage of panels needed). For a larger room, you’ll need to contact us.

2. Rear wall treatment 

The rear wall in a large auditorium or house of worship can produce what’s commonly called slap echoes, or the sharp return of sound. As the speaker’s amplified voice hits the back wall, it is immediately reflected back into the audience. Either cover the entire rear wall with Acoustic Pro sound absorbing wall panels or consider a sound-diffusing treatment.

3. Use the right ceiling shape for your room 

Sound reflections can be useful for speech if they come from the same direction as the speaker and are delayed by less than 30ms. For an auditorium or a large classroom, your acoustics engineer may design a sloped ceiling with acoustic cloud panels to best reflect sound back down to the audience.

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