Aging boomers mean we need to crank up the soundproofing in our housing right now
Otherwise there is going to be a lot more banging on walls and ceilings.
Spouse Kelly and I have been up at our cabin in the woods for a week now, and I have so enjoyed being enveloped in silence, particularly after three nights in a Detroit hotel where they partied in the corridors. Outside of the fridge, there is nothing but the breeze, birds and bugs to make a sound.
My Apple Watch says the background level is 30 dB, which is apparently equivalent to the noise of rustling leaves.
But I don’t even hear that because I rarely put my hearables (my name for hearing aids) in up here. The only time I do is when we are watching a ballgame or a movie; Kelly couldn’t stand it if we set it at the volume I would need to hear the game.
I am spending my time up here working on what I hope will be my next book, The New Manual of the Dwelling, and have been deep into what makes a healthy home. One important aspect is noise; according to the World Health Organization, noise is the second worst environmental stressor for humans after air pollution. It is “associated with increased risk of hypertension, coronary artery disease, stroke, and other cardiovascular problems. It can cause vasoconstriction, elevated blood pressure, and increased levels of stress hormones.” It increases rates of diabetes and dementia. I wrote in a post on Treehugger (deleted, of course) that this was “another good reason to keep quiet streets in place long after the pandemic recedes, and to build better, quieter buildings to keep the noise out.”
I wrote a few years ago on Treehugger about Another Reason to Love Passive House: It's Really Quiet (it’s still there!), quoting Zack Semke, then with nk Architects, who wrote: “Thanks mainly to the greater thickness of both wall and windows, the Passive House wall reduced exterior noise penetration by roughly 10 decibels.”
The decibel scale is logarithmic, with every 10 dB meaning a doubling of noise and vice versa, so a reduction of 10 dB means it is reducing the noise level by 50 percent. That is a serious turning down of the volume.
But Passivhaus walls and windows deal with noise from the exterior; another major source of noise is through the walls and ceilings shared with neighbours. Most building codes specify that shared walls should have an STC (sound transmission class) of 50 dB, representing the amount of reduction that the wall is capable of.
It’s not good enough. As an expert at Commercial Acoustics writes,
“Remember that STC ratings are not the only determinant when deciding how to design a wall. An STC 50 wall may be sufficient for apartment-to-apartment, but may be well below the expectations of a high-end condo. Some litigation refers to “commercially reasonable” expectations of the clients. Somebody spending millions of dollars on a condo may expect to be able to listen to the stereo or TV without having to constantly apologize to neighbors. Meanwhile, STC is really just an “approximation” of how much sound a wall blocks. It does not tell you the wall soundproofing ability at very low frequencies, which are not included in the STC calculation.”
Meanwhile, the problem is just going to get worse, thanks to the baby boomers. As David Foot said in Boom, Bust, and Echo 25 years ago, “Demographics explain 2/3 of everything.” The population is aging rapidly, and more and more aging boomers are moving into apartments. But there are so many issues here; often, new housing units are in “five over one” stick-frame apartments where soundproofing is a function of workmanship rather than a high-mass concrete wall. You are really lucky to hit 50 dB.
Almost all of the aging boomers have hearing loss; everyone does as they get older. According to a Dutch study, “The mean progression of hearing loss was 0.29 and 1.35 dB/year (low and high frequencies).”
It wouldn’t be so bad if people wore hearing aids, but only 29% of adults over 71 years old who need them actually do, and I bet a significant percentage of that 29% do not wear them around the house. They just turn up the volume on the big TV, which has a bigger sound than they ever used to.
So you have a whole pile of different conditions adding up to a big problem:
Aging is the real population bomb, with 20% of the US population over 65 by 2030.
As the population ages, it loses its hearing at a rate of 1.35dB per year.
More and more people are moving into apartments often made of wood frame or mass timber, where acoustic separation is a challenge.
They often buy big-screen home theatres with powerful sound systems and watch their movies at home now.
Even if they have hearing aids, they are probably not wearing them (unless they are married to someone like my wife Kelly).
What we have to do:
Crank up the minimum STC rating for walls to 60, which reduces the amount of noise transfer by half.
We test Passivhaus with a blower door; we need in-situ testing of walls to ensure they meet the rating.
Don’t just rely on STC; it doesn’t count below 125 hertz and according to the Soundproofing company, misses “most of the sound energy generated by the average home theatre.” Other rating systems like the OITC (Outdoor-Indoor Transmission Class) measure lower frequencies.
When I was in Detroit recently and visited Lafayette Park, our guide, an owner of a unit, noted that his second bedroom was actually over the entry of the adjacent unit. I asked him if noise transmission was a problem; he said it was one of the biggest problems in the complex, that you could hear a neighbour’s yappy dog as if it was in your own unit. They put up with it (or spend a lot of money trying to fix it) as one of the prices they pay to live in such a place.
Others will not be so accommodating. Looking at the demographic, construction and even home electronics trends, I suspect that this will become a critical and costly problem if we don’t address it right now.
It may not be worsened by aging boomers, but it's good to also mention impact insulation class (IIC) which is generally caused by footfall. From the data I've seen this is an area where mass timber (when it is left exposed as the finished ceiling) performs poorly vs light wood framing and drywall ceilings that are easily decoupled.
So with the volume turned up to 11 on their giant TVs, the Baby Boomers really are booming.