Improving Acoustics in Learning Spaces
I’ve been thinking about sound a lot in my work lately, and exploring how we can improve acoustics in our schools.
Environment directly impacts student learning. Most conversations along these lines often center on lighting, indoor air quality, even color, but the less-discussed topic of acoustics has significant impacts on a student’s health, behavior, and productivity. This study highlights research findings about the impacts in great detail, although for a quicker introduction to this idea I’d recommend Julian Treasure’s 2012 Ted Talk: let’s design for the ear.
Improvement in this area starts with an entire project team, because it’s not just a design issue. It hinges on decisions made by diverse stakeholder parties, and at all stages of the process. For example, during construction standard acoustic panels in gymnasiums are easy prey when costs need to be reduced. While removing them from your scope can help right-align a project with a budget, it reduces the ability of students and teachers being able to hear one another in what is essentially a very large learning space. If, though, thinking about sound quality is a part of all decision-making, the entire team might find other solutions.
That being said, as a designer I still want to see just how much we can improve on current design best practices and tools. To that end, DLR Group recently partnered with a graduate student mastering in acoustics to evaluate the performance of several U.S. schools. In this study, we measured actual acoustic performance and compared those results to the design intent of those spaces. We looked specifically at the following criteria:
- Reverberation time (RT): How long does it take a sound to bounce back to its source? Construction materials for ceiling, walls and flooring have significant impact on RT. For this study, we measured performance by setting up a room with a source placed in two different locations for three samples and measuring the amount of RT for each.
- Background noise level (BNL): How much ambient outside noise hits the ear? The most common BNL impact inside the learning environment comes from mechanical systems. For each room studied, we essentially closed doors and windows and used equipment to record and analyze ambient noise levels.
- Sound transmission class (STC): How much sound is isolated from one room to the next? The most common impact on STC is with design and construction of separations/enclosures between spaces. To test STC, we generated noise in a room and set up listening equipment in an adjacent room to measure how much was getting through.
We’re still analyzing the results of these test. Based on initial findings, we know already that we can update the Reverberation Time Calculator that we use during design, which will help us become more accurate in the acoustic performance of our designs right away. I’m looking forward to more findings, and hope to share those out in a future article.