robmiller

The nuclear power plant had built the homes to house workers in the early 1980s and to an early form of Energy Star compliance, with an emphasis on being air-tight. Radon was trapped in these homes, workers set off the alarms, and the radon mitigation industry was born.

Just to add a little humanity here among all the numbers, I would have loved to have known my mother. I'm sure adopted children have similar thoughts, but I doubt there's anything quite the feeling of being given life during another's unwitting sacrifice. Would she have changed anything had she known the outcome? It occurred to me from a young age that I should try my best not to squander my opportunities in life.

There are various factors:

1. Partitions around workspaces create a modest barrier effect, not so much realizable for your nearest neighbors but those more distant. No one installs partitions up to 48" or 52" but you have to at least break line of sight to the noisemaker to realize any improvement. This reduces signal.

2. Acoustically absorptive ceilings avoid the overhead reflection that would be the next cue to an occupant. The partition comes first, but this is second. Another signal reducer.

3. Background noise, whether a consistent HVAC system or sound masking system raises the noise floor of the environment. We have a pretty good sense of what level is acceptable to most people, but there will always be those with sensitivities. The noise is usually pink noise with some EQ to sound like HVAC air distribution. Unfortunately there has to be some treble in the noise signal to reduce the consonants of speech, which can be more annoying.

You won't make nearby co-workers inaudible, but the hope is that those 20 ft or so further will be less problematic. For inaudibility you have to get S/N to around -10 dB, that's a noise floor of 10 dB higher than the source, which is only realizable with walls at least to the ceiling.

Hey thanks. Yes, esoteric enough to keep it interesting day to day. I mostly work with architects and design engineers to coordinate quiet building systems and good interior acoustics--projects anywhere from K-12 to major performing arts centers to commercial offices, including some of your US offices...

On that point, I feel everyone's collective pain on the situation with open offices. I don't have the power to avoid them, so the best I can do is advocate for getting the signal-to-noise problem solved right.

Yes, I agree. Inlet side is quieter than discharge for most fan types (propeller, centrifugal, etc), but noise due to air movement are on both sides.

Acoustics consultant here. Its too bad there's no mention of using a windscreen on the sound level meter, especially at 2 inch distance. It would make sense if the mesh performed best, while airflow was restricted nearly most if air rushing by the microphone element was contributing to the level measured, and not the noise of the fan itself.

We use honeycomb panels in acoustics construction as means for high stiffness (low deflection) with the tradeoff of low mass. Often we laminated a thin layer of plywood to each side to improve the stress skin system. Orchestra shell towers are a common example of this, though we are also doing this for portable seating towers that need to reflect sound too. There are both wood pulp and aluminum versions commonly available in the US.

I worked on the design of their US HQ in Redmond. Despite anything the architect could dream up, they like the metaphor of the cube...

My response is US-centric, but most hospital projects do have an acoustics consultant involved. Improvements have been made, but not nearly enough. Challenges include the need for sound absorption to be porous, but this is at odds with cleanability. Increased focus has been on patient room doors, which are increasingly sliders. They work well when they're closed, but the challenges include getting a good bottom seal when the threshold has to accommodate beds and equipment being rolled in and out. Hospital equipment manufacturers are also improving the sounds of their equipment, away from the cheap piezo beepers.

Schools very often have acoustics reviews, although more often in cities than rural areas. Classrooms in addition to auditoria, gyms and common areas. Standards exist for those too.

Office buildings are hit or miss. The developer may hire us for a base building review. Tenants' architects hire us as they design their workplaces. There's a lot of push and pull to find a balance of the modern open ceiling industrial aesthetic and glass conference rooms with reasonable acoustical goals.

Yes, this is in reference to noise passing through a door that is localizable. Typically we would play pink noise (broadband, equal energy per octave band) on one side and listen for "hotspots" on the quiet side. I would wonder about the precision of being able to tell in the image the contribution of the door frame from the perimeter gasketing.

Acoustic cameras like from Noiseless Acoustics are on the market though they seem to be marketed to industrial customers. There are similar mapping systems using a scanning mic like from Soft dB.

I am an acoustics consultant who designs buildings with architects, then sees them through construction. Doors intended to isolate noisy rooms regularly underperform, whether due to manufacturing or installation problems. Lots of fingerpointing when we call it out on project sites, and having a camera show the weaknesses due to the perimeter gasketing, frame, door leaf, or wall construction surrounding the door would provide the necessary visual for contractors to see the problems we are pointing out.