Acoustics really is a complicated subject. Many of our recommendations need to be formed on a case-by-case basis, and some of that advice is based on principles that are not very intuitive. So here is a short list of common acoustical misconceptions:
Acoustical Misconception # 1. Acoustical design is only relevant for specialized projects! Acoustical engineers definitely appreciate sound, and we love to design concert halls and specialty spaces, but sound exists everywhere. Many different spaces benefit from acoustical engineering services such as schools, office buildings, hospitals, and churches to name a few.
Acoustical Misconception # 2. More fuzz please! Contrary to popular belief, the goal of acoustical consulting is not simply to add more fuzz and absorption to a space. Instead, we set a target acoustical environment (for reverberation time, noise isolation, frequency response, background noise level, and more) and then we design the acoustics to meet the criteria.
Acoustical Misconception # 3. Acoustical consultants are only hired when there’s a problem. In fact, when designing a new space, having an acoustical consultant on board from the early design stages can save a lot of time and money by avoiding costly noise issues.
Acoustical Misconception # 4. Small gaps are no big deal. Have you ever shut your bedroom door to block out surrounding noise, but were not satisfied with the reduction? Having a half inch gap at the bottom of the door can be equivalent to having a 4 by 4 1/2 inch hole in the door – plenty of space for sound to get through. It all adds up.
Acoustical Misconception # 5. Painting over acoustic materials doesn’t matter. Although large holes are not helpful (as in the example above), in acoustics, we like the small holes in acoustically absorbent materials that reduce unwanted reflections. Applying a layer of paint over them can seriously compromise the effectiveness of the material. So think twice before you pick up the brush. Some products are available in a variety of colors and others can be painted with a specific type of paint that doesn’t “clog up” all the small holes.
Acoustical Misconception # 6. All foam is created equal. Although it may seem like products that are good thermal insulators should also be effective acoustic insulators, this is simply not the case. Those large sheets of rigid foam (extruded polystyrene in technical terms) that are put into walls are not great sound absorbers. The same goes for non-acoustic packaging foam. Acoustic foam does exist, but it has different properties than your typical construction foam.
Acoustical Misconception #7. Green Glue to the Rescue! We get calls all the time from people who want to block sound with some magical caulk or glue. Although we recommend these types of products in conjunction with more comprehensive sound mitigation strategies, they are never the end-all and be-all of sound isolation.
At Acoustics By Design, we come across these mistakes and misconceptions all the time. Our job is engineer acoustical solutions that stand the test of time. And along the way, we hope to help educate designers on the science of sound.