The Acoustic Performance of Wood
When it comes to construction and design, there’s nothing quite like wood. The right wood can make a building look rustic, elegant, chic, or anything in between.
Wood also makes up the bones of most buildings. Whether in a house built with light-frame construction or a building made with mass timber construction, wood is integral to the structures we spend our time in day in and day out.
In addition to the look and strength of wood, it can also make rooms and buildings sound great. Incorporating wood acoustic panels in designs that make the most out of wood’s acoustic properties is a great way to make your environment look good, feel good, and sound great.
So much music is made with wood—the bodies of string instruments, several percussion instruments as well as pretty much every drumstick, and the reeds that make woodwinds possible are all wooden—that it should come as no surprise that wood is also commonly used architecturally in performance spaces and lecture halls where sound quality is paramount.
Does wood reflect sound, or does wood absorb sound?
The acoustics of wood are so great because there are so many different types and treatments of wood. A wood acoustic guitar produces sound thanks to the resonance chamber made by the body of the instrument. A wood block makes a distinct sound when struck. A wood acoustic panel can do several things.
A fabric-wrapped wood acoustic panel is a very effective sound absorber, while wood acoustic diffusers work wonderfully to disrupt soundwaves for better acoustic quality.
Wood acoustic wall panels allow soundwaves to reverberate and spread through a performance venue with a better tone than you would get through concrete or steel and glass.
So when you ask, “is wood good for acoustics?” the answer is a resounding yes! But it isn’t just suitable for concert halls and lecture rooms. The acoustical properties of wood make it an excellent choice for any design or construction job.
When building with wood—whether light-frame or mass timber—factoring sound quality and transmission is an important part of the design phase. There are four types of sound that good design will address.
Airborne sound from speakers or people talking or impact sound from things falling or neighbors walking around are the types of sound that most people could readily identify as issues.
But designers should also address flanking sounds, which come through tiny cracks and holes, and sound reverberation. Reverberation is caused by sound waves bouncing off surfaces, creating a muddy, underlying noise that can distract and force you to raise the volume on the sounds you actually want to hear.
By understanding the acoustic properties of wood and incorporating those strengths, the sonic landscape of a building can be controlled without sacrificing the warmth and ambiance that wood brings in favor of something more sterile-looking like steel or concrete.
Light-frame wood construction is often found in residential and office buildings. So a major acoustic priority for light-frame construction is keeping airborne and impact sounds in one area from disturbing people in other areas.
Building with materials with high STC (Sound Transmission Class) ratings is the best way to address these needs. Building with high mass partitions and utilizing something like isolation mats under floors are just some of the techniques that can mitigate sound movement.
There are also light mass partition solutions and soft floor finishes or floating hardwood construction that serves the same purpose. But because wood is such a flexible building material and different woods can affect various properties of acoustics, a designer can choose from a large number of sound solutions when building with wood.
Mass Timber Acoustics
Though not as common as light-frame construction, mass timber buildings have their own acoustic strengths and challenges. Because this type of construction utilizes thick, high mass wood for wall and floor construction, the airborne and impact sound issues that light-frame buildings can experience aren’t as much of a problem.
This is not to say steps shouldn’t be taken to mitigate those potential problems. Separating two sides of a wall with decouplers and adding noise barriers behind the wood are effective strategies for addressing those sound types.
Attention should be paid to the places where walls meet floors and ceilings. These are places where flanking sounds can bleed through. It is also essential to examine the reverberation of a room in this kind of building.
The acoustic properties of timber can be a little tricky. While wood will absorb some sound, the flat surface of a timber wall can result in reverberation. Be sure your designer understands the NRC (Noise Reduction Coefficient) ratings of the materials they plan on using.
Incorporating a wood acoustic diffuser or two into the plans for a mass timber project is a great way to control reverberation. And understanding the physics of what it takes to send sound through the wood will help your team make choices in the materials they select.
The Sound of Wood: What is the best wood for soundproofing or the best wood for sound absorption?
The physics of sound can be complicated. Anyone who hasn’t studied it and how acoustic timber and wood sound affects people’s ears in an environment will have many questions.
To get the best answers to these questions and others, work with the experts. Let the ASI Architectural team, who specializes in creating sonically optimal spaces, assist you. The last thing you want is to work with a contractor who doesn’t understand sound and will gladly charge you for “soundproof wood” or something equally shady.
With the right expertise in design and construction, you will have a space that feels welcoming, warm, and classy that also sounds amazing. Reach out to an expert and see how great the sound in the woods can be.