The Basics of Acoustics and Acoustic Panels in Interior Spaces

We’ve all had experiences where unwanted sound interference like noise, echo, and reverb has ruined our day. Maybe it was when eating out at a noisy restaurant and the din from other diners made it impossible to hold a conversation, or you were in the office trying to concentrate on an assignment and all you could hear was Dave from Sales making back-to-back client calls from the other side of the room, or perhaps you’ve been to a theater show where you struggled to hear the actors delivering their lines with the clarity you were expecting. And perhaps you’ve had the opposite experience where you walked into a theatre or restaurant and the acoustically treated room had a satisfying hush that felt calm and serene because the management had used acoustical panels

The sound quality of a room quite often comes down to a misunderstanding of or disregard for the room’s acoustical properties and how that room should be treated to prevent any sound problems.

Understanding Sound Behavior

The sound that you hear when in an interior space can be divided into two categories: the direct sound, which comes straight from the original source (such as the voice of a person sitting directly opposite us) and the reverberant sound, which is when the sound has continued to reflect off surfaces in the room after the sound has stopped. This delay might not be too noticeable in small spaces or where a bit of extra noise is normal, but in a larger room or one where careful listening is important, it can make things challenging for the people in it. Later in this article we have some example scenarios of where this can happen, what the causes might be and what can be done to tackle the problems.

Even though it can be undesirable when it reaches high levels, reverberation should not always be thought of as a bad thing. All interior spaces – even those expertly fitted with acoustic treatment (more to come on that) – are affected by reverberation in at least a small way; it’s about keeping those levels right for that environment. European churches are known for their long reverb times (RT) – medieval churches can have RTs ranging from 2 all the way up to 13 seconds –  but in those spaces it works. Many cathedrals that were built hundreds of years ago are still loved today for their sound characteristics. Without the benefit of modern technology or acoustical conditioning products, many of these structures were originally acoustically designed to suit traditional forms of worship based around choral or organ music that is undeniably enhanced when projected across a big ‘reverb-y’ space. For modern churches though, where more contemporary musical methods are employed, a great deal more sound control is usually required.

Spaces with very little reverberation (perhaps too many acoustic panels) can sometimes feel what we call ‘dry’, which might be okay in a place where clarity of speech is one of the key considerations and also in some contemporary music venues, but in other cases a bit more reverb can liven up the room a bit. A restaurant is a good example, as customers will want to experience a bit of an atmosphere and background ‘buzz’, but of course this has to be limited to maintain the right level of intimacy too. It can be a bit of a balancing act.

If you ever want to find out what it’s like to be in a room where there’s no reverberation then try spending a few minutes in an anechoic chamber, where sound and electromagnetic waves are completely absorbed and no external sound is allowed in at all. It can be a very uncomfortable and unsettling experience.  

Acoustics and Acoustic Panels In the Workplace

Getting the right atmospheric balance with an office environment is a challenge that countless businesses have faced, and it can be hard to get right. What many companies don’t realise is that acoustics and minimising sound interference with acoustic panels should be right near the top of the list of things to consider when planning the office, especially those favouring an open plan layout – one of the most popular arrangements these days.

A noise-free facility is not only crucial for maintaining productivity levels; it’s also a catalyst for good worker morale too. In a recent study from Oxford Economics, ‘the ability to focus and work without interruptions’ was selected as the most important feature of a work environment by employees and over half of the people surveyed said that unwanted ambient noise harmed their workplace satisfaction. Being inundated by multiple audio sources all at once understandably makes it difficult to concentrate and in some cases the noisy atmosphere has even been blamed for high staff turnover.  Acoustic panels on the ceilings or walls of an office can make life so much better.

What are the Causes of Noise Problems?

Noise complications in the office could be due to a lack of sufficient sound-absorbing surfaces, particularly when many of these spaces also have high ceilings. Combine this with hard floors, drywalls and lots of wooden or metal furniture and you’ve got a prime spot for lots of undesirable sound activity. Materials that allow sound to reflect off them are to be avoided; the trouble is, visually they can be quite appealing, which is why they are often chosen for office design projects where making the space look attractive is more of a priority than how the sound is kept under control within it. 

Check out our design-focused, fabric-wrapped acoustical panels here.

It might sound a bit obvious, but being aware of internal or external noise sources that could cause unwanted interference is also important. In an office, upgraded window glazing may be necessary if there’s often heavy traffic outside, and it might not be the best idea to stick the conference room next to the printer or the cafeteria. Acoustical wall panels in hallways and conference rooms can absorb a lot of noise that ruins meetings. HVAC systems, although essential for employee comfort in another way, can become a real nuisance if they’re forgotten at the design phase as well. Having one humming away in a board meeting is not going to please the CEO, but out in a busy communal area it’s unlikely to bother anyone.   

How to Solve Sound Issues?

Instead of simply telling everybody to work in silence – Dave from Sales won’t like that – there are a number of ways to address these sorts of problems effectively.

For enclosed spaces where a lot of discussions will be taking place, treating the walls with acoustic panels or tiles will help absorb the sound and prevent it from bouncing from surface to surface.

If there is a lot of space overhead then it might be worth considering something like a ceiling baffle system, another great noise mitigation tool. Rooms with high ceilings often suffer from long reverberation times as well, but this time due to the sound travelling more vertically.

Finally, simply laying down rugs and carpets around communal spaces can also help prevent sound from reflecting off the floor.

Other Acoustics and Sound Problems to Avoid

Sometimes, the problem is less to do with reverberation and absorption and more to do with poor sound isolation, particularly in a place with individual zones where users want as little interference from outside their zone as possible. Again, an office with small private meeting spaces would be a good example. In these areas, having walls with a bit of extra density would help protect against unwanted sound transfer in and out of the space.

Even in a room treated for sound absorption and with dense walls, sound leakage can still persist through what are known as flanking paths. This is when the sound is able to find its way over, under or around a wall. It is therefore important that a room is properly sealed in the right places to be considered in any way soundproof.

It is easy to imagine how sound leakage would be possible between two rooms connected by an air vent system, but it can also happen in more inconspicuous ways. For example, if your neighbor is being noisy despite there being what appears to be a well-sealed, thick wall in the way, it could be because of a connected flooring system or ceiling joist between the two properties, which you can’t see but you can bet that sound will find its way through.  

Another type of noise that can cause problems is also common in residential buildings: impact noise. This occurs when an object strikes another, making a sound which then causes a structural vibration on a wall, floor or ceiling, resulting in it being heard on the other side of that surface. A good example would be when you can hear footsteps coming through the hardwood floor of the room above in an apartment block. If they were to replace their hardwood floor with a carpet then it would reduce the sound coming through significantly, as the material of the carpet would help reduce the vibrations making it through to the structure underneath through which the sound would otherwise travel.  

Sound Control in Larger Spaces

Acoustic oversights can become even more noticeable in a larger interior space, especially one where at least a decent level of audio quality is expected by multiple listeners, like an auditorium or lecture hall. In these places, speech intelligibility is crucial. The last thing you want is for students to not be able to hear the lecturer clearly.

Here, the sound (e.g. the lecturer’s voice) must travel a greater distance to reach the people sitting at the back of the room, and if the reverb hasn’t been dealt with properly then you could have reflections coming back in the opposite direction, maybe bouncing off the side walls as well.

Add a loudspeaker system into the mix and it can sometimes make matters worse rather than better in a room with insufficient treatment. Quite often it’s the technology that’s blamed when issues arise when in fact it’s the acoustics where the problems lie. If you have a space that’s poorly designed for sound distribution then you could put the world’s best PA system in there and it will still sound terrible. This explains why a lot of AV contractors will insist that the room’s acoustics are perfected before moving on to what equipment is needed. They’ll often employ acoustic panels to condition the room which improves the feel of it by cutting echo and noise.

That being said, the opposite can still apply – you might have spent a premium on hiring the best acoustician going, but if there was only enough left in the budget to buy the cheapest PA available or if the placement of the speakers is not right then that can be just as troublesome, or worse.

Talk to the Acoustics Experts

The best way to ensure that a space doesn’t suffer from sound issues is to make acoustics a key part of the whole design process from the beginning. For those thinking about designing a new space, appointing an acoustician should be considered just as important as bringing in someone who knows a thing or two about interior design. It’s always a lot easier – not to mention cheaper – to factor in sound control in the early stages as any potential complications can be addressed before all the expensive build work has been done.  

The experts will have done a similar job multiple times before and know exactly what needs to go where, even if the space happens to be a little unusual in terms of size, shape or interior features.

Conclusion - Acoustic Panels for Indoors

Sound quality has always been considered by many to be less important than visuals. How many of us have gone out and bought a brand-new high-end TV but didn’t even think about adding a soundbar, acoustic panels on the walls, or maybe a few surround speakers? Yes, you might have amazing picture quality now, but you’ll be missing out on so much detail if you opt to rely on just those built-in speakers. Quite often, audio only really enters a person’s consciousness once it becomes a problem, when in reality it’s a crucial factor that should never be side-lined.

It’s the same with interior space design – of course having it look nice is important, but you won’t be able to get that coveted ‘vibe’ with a venue if you’re willing to let the sound run wild. Because it cannot be seen, people are often unsure about how to deal with sound issues or where to begin with acoustic panels and acoustic treatments. But as we’ve explained here, once you understand the causes and solutions, which probably aren’t actually as complicated as you might think, there will always be a way to address them. The best to start is to take a look at our acoustical panels that come in a variety of standard or even custom sizes, shapes and colors. Best of luck and don’t let the unseen world of errant sound waves ruin a great sound system.