Become an Acoustic Expert in 2 Minutes with this Crash Course
Miss the office? Are you sure? Conniption fit Karen always popping off about her food going missing and not having enough milk to saturate her Frosted Flakes is not really that Grrrreat, is it? Super sensitive Sam always whining about the firmness of the tofu in his poke bowl, and the high pitched wail when “they forgot my seaweed AGAIN?”
We may miss the human interaction, but we certainly don’t miss the interruptions and the constant distraction of sounds, or as we called the unpleasant version: noise.
But we are designing for these things today and including these in our considerations of our comfort, our space and our sanity. So let’s get smart and savvy on sound in sub sixty seconds.
Ways that sound is measured:
STC: Sound Transmission Class is a measure of how well something attenuates or reduces airborne sound between rooms. So if you can’t hear crazy Karen screaming that someone nicked her nuggets in the break room adjacent to your office, your wall has a good STC.
NRC: Noise Reduction Coefficient is an average of how much sound an object can absorb. So when Sam sees the seaweed is missing & slams his suffering head against the wall, but isn’t further put off by the echo, we have a good NRC. (It was probably something soft like Kirei EchoPanel, good choice.)
IIC: Impact Insulation Class addresses the noise that occurs between floors as a result of footfall or other physical contact with the surface above that is heard in the space below. Clickity Clack Karen in her calico Calvin Kleins keeping you up at night? Because she lives upstairs, we mean. A floor with a good IIC, like cork flooring, can help with that (or carpet, Karen, carpet.)
dB: Decibels are a unit of measurement for sound. You could safely say Karen’s cackle has a higher decibel level than Sam’s soft sobs.
Sabin: This is a measure of acoustic absorption equivalent to one square foot of a perfectly absorptive surface. Not an Alabama football coach. Materials deliver Sabins in terms of the acoustic absorption they offer. So, a hard surface like Karen’s head delivers more Sabins and a soft surface like Sam’s cry pillow. The more absorptive the material, and the more surface area, the more Sabins, for the win.
Terms for how sound is affected:
Absorption: How effective materials are at reducing the amount of sound energy that is reflected back into a space. The more absorptive a material, the more sound energy is reduced and less is reflected back into the space. This is different from self absorption, for which Sam I Am is notorious.
Transmission: How much energy passes through a material, like a wall, floor, door or window. There are multiple types of transmission, including airborne, impact and flanking transmission. Kind of like how it goes in one ear and out the other when Karen calls to complain.
Reflection: How much sound energy is returned into a space after it strikes a material as opposed to being transmitted or absorbed. (Not the same as the reflection that stops Sam in his tracks to preen his coiffed hair on the way to the water cooler with his humongous Hydro Flask.)
Reverberation (time): The persistence of sound energy in a space after reflection, when sound continues even after the source has stopped producing sound. The Rt, or reverberation time, is the time it takes for the sound to decrease 60 dB from its steady-state value once the source of sound energy has been stopped. Crouton Karen bitching about the amount of lettuce in her Chicken Caesar in a room with a long Rt would be…excruciating.