Imagining building a bridge and then in the middle someone comes along and says it should also be a tunnel
While converting a bridge to tunnel mid-construction doesn't happen, what does often happen is that design assumes a particular construction technique can be used, construction starts with that technique, and midway through it's determined that an entirely different technique is required. This results in a bunch of redesign, remobilization, etc. Just like with software, construction often does not survive first contact with reality.
noise pollution (it’s really worth watching Benn Jordan’s video on infrasound,)
Noise from data centers is a real issue, but Benn's measurements and analysis are not great (speeding up the sample rate to demonstrate frequency effects is just wrong, among other issues).
Spring 2020, they released the iPhone SE 2020, 4 years after the previous iPhone SE. This satiated a lot of the demand for people holding out for a smaller phone.
Count me in this group. I wound up buying the 13 mini right before it was going to be discontinued because I knew that would be the last small phone they would produce and I'm keeping it until it dies (or I can't get a battery for it).
If you're going through the hassle of reseting your iPhone to set with Configurator, you should think about pair locking your phone while you're at it:
Analyzing security footage for potential suspects should be done by police.
Again, it's not just "potential suspects" it's potential witnesses, or identification of potential casualties. I don't feel great about state actors of any type using facial ID, but I can think of any number of reasons why a FD might use it in the course of their duties, and I would much prefer they have it over the PD.
The job of the fire department should be to fight fires, not to investigate crimes.
Part of the investigation is determining whether the event is actually a crime. I'd much rather have subject matter experts make the determination of arson vs. act-of-god rather than "every nail needs a hammer" police force.
I wish there were an expert or researcher interested in these areas: residential buildings, shops, parks, churches, and schools.
You mean an expert in acoustics related to those areas? There are lots of experts and researchers. Take a look at the Acoustical Society of America, the Institute of Noise Control Engineering, and Council for Accreditation in Occupational Hearing Conservation for starters.
Penn State, University of Hartford, Purdue University, Michigan Technological University, University of Nebraska, Morgan State Univeristy, and Brigham Young University (among others) all have strong acoustics programs with research in a bunch of areas.
I've tried searching the literature to find out whether this is either 1)wrong, or 2)generally known within the fields of audiology and occupational hygiene, but so far I've come up empty.
FWIW, I've also heard the same, but don't remember where off the top of my head. It's at least potentially true, but the conventional wisdom among acousticians/noise control engineering is that age-related hearing loss is mostly to increasing age rather than external factors.
FYI, there's been tons of research of the effects of noise on sleep from different sources. There have been studies ranging from in-lab experiments, to in-home experiments with artificial and natural sources. If you're interested, some resources:
Acoustical Society of America Lay Language Papers: https://acoustics.org/lay-language-papers/ (search for "sleep" -- the ASA has a full library of more detailed research but the documents cost money unless you're an ASA member)
A lot of the stuff that posters are asking for have in fact been done, it just takes some digging through the research sites to find them. There's a lot of variation in the data, the hypothesis is that sleep sensitivity varies a lot based on various physical factors (age being a big one).
Ron is a fixture at acoustics conferences, he's a nice guy and was very passionate about making the facility work when he was raising funds in the aughts. If you're going to be in the area and give him enough notice, he'll be happy to give you a tour.
Last I heard (which was admittedly about 10 years ago, things may have changed since then), the facility was struggling a bit. It's true that these types of testing facilities need quiet background noise levels for testing, but that can usually be achieved either through putting the facility in the middle of nowhere, or over-engineering the structure. NWAA obviously has both, but that results in increased costs. On the other hand, you have facilities like Orfield Labs and Microsoft's newest anechoic chamber that manage to be _very_ quiet while still located in relatively convenient areas. Plus many audio/speaker/acoustical products companies have their own facilities.
That said I'm glad NWAA is still getting press and I hope it remains a fixture for generations to come. We need more of these moonshots.
The implication is that we're talking about sound pressure level in air, therefore the reference pressure would be 20 µPa.
and for which frequencies?
Again, the implication is annoyance and in that context I'm looking at overall SPL in A-weighted decibels (A-weighted decibels, while not perfect, is reliably correlated with annoyance)
I think you don't really know
For the record I'm an expert [0] in acoustics and noise control. It's how I've made my living for the past 30 years. So yes, I really know.
or you would have specified
I wasn't trying to get into a detailed discussion here, but I'm happy to oblige for anyone that wants to learn.
as with most things relating to acoustics, the truth appears to be extremely complicated
Absolutely. That said, if you look at the link, the author mentions 8-9 dB of excess attenuation with 50 meters of intervening foliage. That correlates to about 1 dB of attenuation per 18 feet of foliage. Again, that demonstrates that a strip of foliage would do almost nothing to reduce sound levels. And for what it's worth, the phonemea the author is describing is not "absorption" - it's a combination of partial cancellation of the reflected/direct wave interaction in porous soil (same reason why snow covered ground makes things quieter) and refraction from leaves/trunks (which is why the foliage needs to be _dense_, otherwise soon waves travel through the gaps and provide no reduction).
[0] By "expert" I mean a) studied the subject as an undergrad at MIT b) worked for 30 years in the field, producing or contributing to several hundred Environmental Impact Statements in the USA, authoring/co-authoring a couple dozen papers and presentations including one peer-reviewed study, c) authored or contributed to acoustics guidance manuals for the U.S. Federal Transit Administration, Federal Aviation Administration and National Academies, d) have been admitted as an expert witness in acoustics/noise control in criminal and civil trials in seven states, e) have certification demonstrating noise control expertise [1], f) been recognized by my peers as having contributed to the field, g) have had research referenced by international researchers
> Can you plant bushes or shrubs between you and the road?
A thin strip of foliage does (basically) nothing to reduce noise propagation. Dense foliage (meaning you can’t see anything through it or move through it) gets you about 1 dB reduction for every 10 feet of thickness.
The paper basically reinforces one of the tenets of transit noise and vibration analyses: if you don't maintain your system (specifically wheels and rails in the case of noise), things tend to get louder over time. BCRTC knows this [0] and they're working on it. As with all things, it's about time and money, but they are trying to be proactive with vehicle and track maintenance via rail grinding and complaint tracking.
Which is the same constraint as pretty much any other physical item one might purchase. "reasonably a forever" is a reasonable description.