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:
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.
Determining if it was an arson vs act-of-god should be mostly lab work, analyzing how the fire spread, whether there are any traces of flammable substances that should not be there, etc. That's what fire department should do, because they have expertise here. Analyzing security footage for potential suspects should be done by police.
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.
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.
That might make you want to look at that list of organizations and then seek similar organizations or schools in Singapore, if you didn't already try. Good luck with the hum.
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).
Interestingly, there's been some suggestion that hearing loss is not inevitable with age, but is mostly just the accumulation of noise-related hearing loss in a loud industrial society.
I think partly the issue is that how we measure noise doesn't match how noise causes injury. Your cochlea acts as a spiral resonant tube, essentially a "physical FFT," concentrating energy at a particular frequency onto a particular location in the spiral. Too much (local!) energy damages the hair cells, causing conductive hearing loss.
But because we calculate A-weighted decibels by summing all frequencies and then checking if we're above the injury threshold (vs checking whether we exceed the injury threshold at any frequency), using A-weighted decibels can't accurately determine damaging noise levels. If all the energy is concentrated at Middle A it will cause more damage than spreading the energy out across the spectrum, even if the A-weighted decibels come out equal.
It's a somewhat subtle, wrong order-of-operations problem. There's also a separate problem that A-weighting is designed to normalize for perception at various frequencies, not hearing damage.
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.
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I recall an HN poster long ago saying how they wore earplugs daily to achieve "super hearing." It occurs to me that all they were doing was actually protecting their ears from damage. :-|
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.
Oh, I meant about the wrong order-of-operations problem with decibels, which I have never seen anyone talk about. If you've heard of it please let me know.
The links discuss the evidence that hearing loss isn't inevitable with age, including examples of pre-industrial societies with quiet environments that when tested showed no hearing degradation with age.
The controversy seems to be mostly about how much of that effect was caused by good diet vs lack of exposure to loud sounds. I tend to think both are needed to be fully protective, eg to take an extreme example alcohol is known to cause damage to hearing cells even without exposure to loud sounds.
I expect, with apologies to Tolstoy, "All dysfunctional hearing is different, whereas all healthy hearing is the same."
And that issue is non-starter, for the same reasons given in the podcast you even linked:
> GDP is just GDP. It's just like, how big is the economy? It's not that hard. And you can't take the government part out of it because the government is a significant part of that.
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.
> 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.
one decibel reduction at what reference pressure, and for which frequencies? I think you don't really know, or you would have specified.
as with most things relating to acoustics, the truth appears to be extremely complicated[0] and foliage has different effects at different frequencies including reflection (which may perceived as amplification in some scenarios)
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
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.
https://reincubate.com/support/how-to/pair-lock-supervise-ip...