by Kevin Herreman
If silence is golden, good acoustics may be priceless. Acoustic challenges have become very common place as millions have transitioned to working from home during the pandemic. As parents worked in one room while children attended their online classes in another, and doorbells and dogs became standard background noise, millions of workers got a crash course on how to use the mute button during video conferences.
The repercussions of the pandemic will no doubt play out in adaptations to the building enclosure and interior spaces. While social distancing, access to outdoor air, and filtration are projected to be likely areas of focus in future enclosures, acoustic design is also likely to be given more attention. From interior wall assemblies to open plan and exposed structure designs, architects must consider how materials specified for the interior and enclosure will enhance or detract from the quality of the sound in the space. Planning for the quality of the sound at the design stage can result in a building that delivers occupant comfort and drives positive outcomes, including patient satisfaction, speech privacy, and employee productivity.
The sounds of change
Even prior to the pandemic, trends in the choice of construction materials and preferences for interior furnishings were changing the fundamental sound profile of buildings.
The specification of lighter weight materials, such as laminate claddings and more vision glass, has resulted in less sound reduction from outdoor to indoor environments since these do not block sound as well as more opaque materials. The choice of an innovative material to solve one problem can result in a tradeoff between different performance attributes. For example, laminate façades are easier to install, but can allow more outside noise to infiltrate a space compared to traditional masonry. On the interior, lightweight drywall use can result in an increase in measurable sound transmission between partitions. It is easier to work with during the construction of the spaces, but with a lower density, it can make it possible to hear a conversation in the next room.
Interior design preferences are changing, too, with many commercial buildings eschewing upholstered furniture and carpeting in favor of hard surfaces that wear longer and are easier to clean and sanitize. Not only does an increase in hard surfaces reduce sound absorption, but also can create a new kind of noise (think classroom chair legs dragging across laminate flooring on the story above).
By considering noise issues during the design phase, architects and designers can make material and design decisions that reduce the need for expensive, after-the-build sound mitigation strategies. This approach can not only save costs on a building’s interior finishes, but also avoid issues that could be cost-prohibitive to completely solve once the structure is established.
How sound affects occupants
Some studies have correlated negative health effects like stress and rising blood pressure with exposure to loud, persistent industrial noises. Sound concerns in non-industrial spaces, particularly in workplace settings, are more subtle and may also lead to long-term health issues. The sound of water flushing through pipes in an adjacent room or the transmission of sound through a ceiling plenum space or air ducts can lead to problems with communication, comfort, and privacy.
In hospitals, noise is the number one complaint of patients, staff, and visitors. Studies have shown noise interferes with patient sleep and even impacts the healing process. For children, a noisy learning environment that makes it harder to hear the teacher can be associated with measurable cognitive effects. Not all sounds provoke the same response; high-frequency noises, such as fire alarms or whistles, tend to be immediately distracting, but low-frequency noise like mechanical systems powering up or the rumble of thunder outside is much more insidious.