We all have instinctual reactions when we enter a room and perceive how sounds and voices affect the space. Entering an open layout room with tall ceilings and hard surfaces where voices and environmental noise reverberate, for example, can create a harsh and unpleasant atmosphere. Workspaces without acoustic treatment can have the same effect if there are many hard surfaces and objects for sounds to bounce off. These can include glass walls, whiteboards, and large computer or presentation screens.
Neurologists have proven that the quality of acoustic environments can have a significant impact on a brain's ability to construct accurate sound images. To understand this, we have to look at some of the science around how sound behaves. Even in small meeting rooms and huddle spaces, reflected sound waves register with our brain later than the initial sound waves. Since sound travels at about 1,130 feet per second, a room that measures 20 feet in length would have a sound wave that travels back and forth between the walls about 55 times in one second.
Because sound moves in 360 degrees, rooms with many reflective surfaces also allow reflected sounds to mix and interact with each other. This makes it difficult to hear clearly when only a few people are gathered in the room. Acoustic treatment options have advanced over the years to provide out-of-sight, aesthetically pleasing options to reduce sound reflection.
There's a wide range of acoustic treatment options for soundproofing conference rooms, which enables organizations to customize solutions for all meeting areas in different office settings.
All noise reduction materials for a commercial setting like a conference room come with a noise reduction coefficient (NRC) rating (from 0.00-1.00+) that measures the amount of sound energy they absorb. Materials with an NRC of .75 or more — which translates to absorbing 75% of the sound energy generated nearby — are considered highly effective at addressing noise issues.
Some materials that are most successful at absorbing sound include cork, fiberglass, stone wool, and sprayed cellulose fibers.
Conference room acoustic treatments can be broken up into three categories: sound masking, soundproofing, and sound absorption. Sound masking features include white noise devices and loudspeakers used to emit soundwaves that cancel out the audio coming from a space. Soundproofing includes structural options like soundproof drywall and windows specifically designed to deaden sound. Sound absorption options include drop ceilings with acoustical ceiling tile, acoustic baffles and partitions, mounted acoustic panels on doors and walls — ranging from foam to designed art panels — and sound-dampening curtains.
We'll look at some of the more popular acoustic treatment options and considerations for improving the sound in a workspace.
Baffles are noise-absorbing panels hung from the ceiling or on a wall and can be constructed with an aluminum frame for support — next time you're in a theater, look at the surrounding walls and you'll see the multiple baffles or fins mounted on the walls and even the ceilings. They come in a variety of shapes and sizes and are typically made of fiberglass, foam, and cotton core — or they may be wrapped in a print fabric to blend into the design of the space. When created with an artistic design on the fabric wrap, a baffle can make the room more pleasant both visually and acoustically without being intrusive or distracting.
The thickness of baffles can vary from a couple of inches to nearly a foot, with higher frequency sounds needing thicker structures for suitable sound dampening. Pricing options for baffle structures can start at under $50 USD per piece, though those specifically designed for office spaces and conference rooms can range from $200 USD to $500 USD.
Acoustic ceiling tile is one of the more popular options for sound absorption in spaces where a drop ceiling can work with existing HVAC and regulatory requirements. The tiles can soak up sounds to prevent the waves from reflecting around the room. They can also block most sound from traveling into adjacent rooms, reducing ambient noise.
Ceiling tiles should come with an NRC of at least .70. Installing them via a drop ceiling framework can also reduce the height of a room by six inches at most. Tiles typically come in 2-foot square sections or in 2x4 rectangles. Costs for the tiles generally run from $25 USD to $40 USD each, but high-end sets of 12 or more can cost $100 USD per tile for select woods.
Acoustic panels are typically made of compressed mineral wool or foam that "cleans" a meeting area of sound debris, which can disrupt collaboration and presentations.
Panels are often preferred because the fibers or pores in their material vibrates from the sound energy, increasing friction with the pores and fibers around them and transforming the sound energy into kinetic or motion energy. This energy quickly dissipates without reflecting the original nearby sound energy.
Much like some acoustic ceiling tiles, acoustic panels are offered in a standard size of 2 feet by 4 feet at a thickness of 2 to 4 inches. Most acoustic materials suppliers also offer custom sizes at larger sizes up to 4 feet by 8 feet. Panels come in a wide variety of colors, and some suppliers offer custom visual art treatments to add a decorative touch. Acoustic panels are also typically arrayed in sets of three, with prices ranging from $25 USD to more than $200 USD each.